这篇文章按照字母顺序列出了MDN里边所有的JavaScript方法。

Found 441 pages with the tag "Method":

## A

- `abs`: The `Math.abs()` function returns the absolute value of a number, that is
- `acos`: The `Math.acos()` function returns the arccosine (in radians) of a number, that is
- `acosh`: The `Math.acosh()` function returns the hyperbolic arc-cosine of a number, that is
- `add`: The static `Atomics``.add()` method adds a given value at a given position in the array and returns the old value at that position. This atomic operation guarantees that no other write happens until the modified value is written back.
- `add`: The `add()` method appends a new object to the end of a `WeakSet` object.
- `add`: The `add()` method appends a new element with a specified `value` to the end of a `Set` object.
- `all`: The `Promise.all()` method returns a single `Promise` that resolves when all of the promises passed as an iterable have resolved or when the iterable contains no promises. It rejects with the reason of the first promise that rejects.
- `anchor`: The `anchor()` method creates an `<a>` HTML anchor element that is used as a hypertext target.
- `and`: The static `Atomics``.and()` method computes a bitwise AND with a given value at a given position in the array, and returns the old value at that position. This atomic operation guarantees that no other write happens until the modified value is written back.
- `apply`: The `apply()` method calls a function with a given `this` value, and `arguments` provided as an array (or an array-like object).
- `apply`: The `handler.apply()` method is a trap for a function call.
- `apply`: The static `Reflect``.apply()` method calls a target function with arguments as specified.
- `asIntN`: The `BigInt.asIntN` static method is used to wrap a BigInt between -2width-1 and 2width-1-1.
- `asUintN`: The `BigInt.asUintN` static method is used to wrap a BigInt between 0 and 2width-1.
- `asin`: The `Math.asin()` function returns the arcsine (in radians) of a number, that is
- `asinh`: The `Math.asinh()` function returns the hyperbolic arcsine of a number, that is
- `assign`: The `Object.assign()` method is used to copy the values of all enumerable own properties from one or more source objects to a target object. It will return the target object.
- `atEnd`: The `Enumerator.atEnd` method returns a Boolean value indicating if the enumerator is at the end of the collection.
- `atan`: The `Math.atan()` function returns the arctangent (in radians) of a number, that is
- `atan2`: The `Math.atan2()` function returns the angle in the plane (in radians) between the positive x-axis and the ray from (0,0) to the point (x,y), for `Math.atan2(y,x)`.
- `atanh`: The `Math.atanh()` function returns the hyperbolic arctangent of a number, that is

## B

- `big`: The `big()` method creates a `<big>` HTML element that causes a string to be displayed in a big font.
- `bind`: The `bind()` method creates a new function that, when called, has its `this` keyword set to the provided value, with a given sequence of arguments preceding any provided when the new function is called.
- `blink`: The `blink()` method creates a `<blink>` HTML element that causes a string to blink.
- `bold`: The `bold()` method creates a `<b>` HTML element that causes a string to be displayed as bold.

## C

- `call`: The `call()` method calls a function with a given `this` value and arguments provided individually.
- `catch`: The catch() method returns a `Promise` and deals with rejected cases only. It behaves the same as calling `Promise.prototype.then(undefined, onRejected)` (in fact, calling `obj.catch(onRejected)` internally calls `obj.then(undefined, onRejected)`). This means, that you have to provide `onRejected` function even if you want to fallback to `undefined` result value - for example `obj.catch(() => {})`.
- `cbrt`: The `Math.cbrt()` function returns the cube root of a number, that is
- `ceil`: The `Math.ceil()` function returns the smallest integer greater than or equal to a given number.
- `charAt`: The `String` object's `charAt()` method returns a new string consisting of the single UTF-16 code unit located at the specified offset into the string.
- `charCodeAt`: The `charCodeAt()` method returns an integer between 0 and 65535 representing the UTF-16 code unit at the given index.
- `clear`: The `clear()` method removes all elements from a `Map` object.
- `clear`: The `clear()` method used to remove all elements from a `WeakSet` object, but is no longer part of ECMAScript and its implementations.
- `clear`: The `clear()` method used to remove all elements from a `WeakMap` object, but is no longer part of ECMAScript and its implementations.
- `clear`: The `clear()` method removes all elements from a `Set` object.
- `clz32`: The `Math.clz32()` function returns the number of leading zero bits in the 32-bit binary representation of a number.
- `codePointAt`: The `codePointAt()` method returns a non-negative integer that is the Unicode code point value.
- `compare`: The `Intl.Collator.prototype.compare()` method compares two strings according to the sort order of this `Collator` object.
- `compareExchange`: The static `Atomics``.compareExchange()` method exchanges a given replacement value at a given position in the array, if a given expected value equals the old value. It returns the old value at that position whether it was equal to the expected value or not. This atomic operation guarantees that no other write happens until the modified value is written back.
- `compile`: The `WebAssembly.compile()` function compiles a `WebAssembly.Module` from WebAssembly binary code. This function is useful if it is necessary to a compile a module before it can be instantiated (otherwise, the `WebAssembly.instantiate()` function should be used).
- `compile`: The deprecated `compile``()` method is used to (re-)compile a regular expression during execution of a script. It is basically the same as the `RegExp` constructor.
- `compileStreaming`: The `WebAssembly.compileStreaming()` function compiles a `WebAssembly.Module` directly from a streamed underlying source. This function is useful if it is necessary to a compile a module before it can be instantiated (otherwise, the `WebAssembly.instantiateStreaming()` function should be used).
- `concat`: The `concat()` method concatenates the string arguments to the calling string and returns a new string.
- `concat`: The `concat()` method is used to merge two or more arrays. This method does not change the existing arrays, but instead returns a new array.
- `construct`: The static `Reflect``.construct()` method acts like the `new` operator, but as a function. It is equivalent to calling `new target(...args)`. It gives also the added option to specify a different prototype.
- `construct`: The `handler.construct()` method is a trap for the `new` operator. In order for the new operation to be valid on the resulting Proxy object, the target used to initialize the proxy must itself have a `[[Construct]]` internal method (i.e. `new target` must be valid).
- `copyWithin`: The `copyWithin()` method shallow copies part of an array to another location in the same array and returns it, without modifying its size.
- `copyWithin`: The `copyWithin()` method copies the sequence of array elements within the array to the position starting at `target`. The copy is taken from the index positions of the second and third arguments `start` and `end`. The `end` argument is optional and defaults to the length of the array. This method has the same algorithm as `Array.prototype.copyWithin`. TypedArray is one of the typed array types here.
- `cos`: The `Math.cos()` static function returns the cosine of the specified angle, which must be specified in radians. This value is
- `cosh`: The `Math.cosh()` function returns the hyperbolic cosine of a number, that can be expressed using the constant e:
- `create`: The `Object.create()` method creates a new object, using an existing object as the prototype of the newly created object.
- `customSections`: The `WebAssembly.customSections()` function returns a copy of the contents of all custom sections in the given module with the given string name.

## D

- `defineProperties`: The `Object.defineProperties()` method defines new or modifies existing properties directly on an object, returning the object.
- `defineProperty`: The static `Reflect``.defineProperty()` method is like `Object.defineProperty()` but returns a `Boolean`.
- `defineProperty`: The static method `Object.defineProperty()` defines a new property directly on an object, or modifies an existing property on an object, and returns the object.
- `defineProperty`: The `handler.defineProperty()` method is a trap for `Object.defineProperty()`.
- `delete`: The `delete()` method removes the specified element from a `WeakSet` object.
- `delete`: The `delete()` method removes the specified element from a `Map` object by key.
- `delete`: The `delete()` method removes the specified element from a `WeakMap` object.
- `delete`: The `delete()` method removes the specified element from a `Set` object.
- `deleteProperty`: The static `Reflect``.deleteProperty()` method allows to delete properties. It is like the `delete` operator as a function.
- `deleteProperty`: The `handler.deleteProperty()` method is a trap for the `delete` operator.
- `dimensions`: The `VBArray.dimensions` method returns the number of dimensions in a VBArray.

## E

- `endsWith`: The `endsWith()` method determines whether a string ends with the characters of a specified string, returning `true` or `false` as appropriate.
- `entries`: The `entries()` method returns a new `Array Iterator` object that contains the key/value pairs for each index in the array.
- `entries`: The `entries()` method returns a new `Array Iterator` object that contains the key/value pairs for each index in the array.
- `entries`: The `entries()` method returns a new Iterator object that contains the `[key, value]` pairs for each element in the `Map` object in insertion order.
- `entries`: The `entries()` method returns a new `Iterator` object that contains an array of `[value, value]` for each element in the `Set` object, in insertion order. For `Set` objects there is no `key` like in `Map` objects. However, to keep the API similar to the `Map` object, each entry has the same value for its key and value here, so that an array `[value, value]` is returned.
- `entries`: The `Object.entries()` method returns an array of a given object's own enumerable string-keyed property `[key, value]` pairs, in the same order as that provided by a `for...in` loop (the difference being that a for-in loop enumerates properties in the prototype chain as well). The order of the array returned by Object.entries() does not depend on how an object is defined. If there is a need for certain ordering then the array should be sorted first like `Object.entries(obj).sort((a, b) => b[0].localeCompare(a[0]));`.
- `enumerate`: The `handler.enumerate()` method used to be a trap for `for...in` statements, but has been removed from the ECMAScript standard in ES2016 and is deprecated in browsers.
- `enumerate`: The static `Reflect``.enumerate()` method used to return an iterator with the enumerable own and inherited properties of the target object, but has been removed in ECMAScript 2016 and is deprecated in browsers.
- `eval`: The `Object.eval()` method used to evaluate a string of JavaScript code in the context of an object, however, this method has been removed.
- `every`: The `every()` method tests whether all elements in the array pass the test implemented by the provided function.
- `every`: The `every()` method tests whether all elements in the typed array pass the test implemented by the provided function. This method has the same algorithm as `Array.prototype.every()`. TypedArray is one of the typed array types here.
- `exchange`: The static `Atomics.exchange()` method stores a given value at a given position in the array and returns the old value at that position. This atomic operation guarantees that no other write happens between the read of the old value and the write of the new value.
- `exec`: The `exec()` method executes a search for a match in a specified string. Returns a result array, or `null`.
- `exp`: The `Math.exp()` function returns `ex`, where `x` is the argument, and `e` is Euler's number (also known as Napier's constant), the base of the natural logarithms.
- `expm1`: The `Math.expm1()` function returns `ex - 1`, where `x` is the argument, and e the base of the natural logarithms.
- `exports`: The `WebAssembly.exports()` function returns an array containing descriptions of all the declared exports of the given `Module`.

## F

- `fill`: The `fill()` method fills all the elements of a typed array from a start index to an end index with a static value. This method has the same algorithm as `Array.prototype.fill()`. TypedArray is one of the typed array types here.
- `fill`: The `fill()` method fills (modifies) all the elements of an array from a start index (default zero) to an end index (default array length) with a static value. It returns the modified array.
- `filter`: The `filter()` method creates a new array with all elements that pass the test implemented by the provided function.
- `filter`: The `filter()` method creates a new typed array with all elements that pass the test implemented by the provided function. This method has the same algorithm as `Array.prototype.filter()`. TypedArray is one of the typed array types here.
- `finally`: The `finally()` method returns a `Promise`. When the promise is settled, i.e either fulfilled or rejected, the specified callback function is executed. This provides a way for code to be run whether the promise was fulfilled successfully or rejected once the `Promise` has been dealt with .
- `find`: The `find()` method returns a value in the typed array, if an element satisfies the provided testing function. Otherwise `undefined` is returned. TypedArray is one of the typed array types here.
- `find`: The `find()` method returns the value of the first element in the array that satisfies the provided testing function. Otherwise `undefined` is returned.
- `findIndex`: The `findIndex()` method returns an index in the typed array, if an element in the typed array satisfies the provided testing function. Otherwise -1 is returned.
- `findIndex`: The `findIndex()` method returns the index of the first element in the array that satisfies the provided testing function. Otherwise, it returns -1, indicating no element passed the test.
- `fixed`: The `fixed()` method creates a `<tt>` HTML element that causes a string to be displayed in fixed-pitch font.
- `flat`: The `flat()` method creates a new array with all sub-array elements concatenated into it recursively up to the specified depth.
- `flatMap`: The `flatMap()` method first maps each element using a mapping function, then flattens the result into a new array. It is identical to a map followed by a flat of depth 1, but `flatMap` is often quite useful, as merging both into one method is slightly more efficient.
- `floor`: The `Math.floor()` function returns the largest integer less than or equal to a given number.
- `fontcolor`: The `fontcolor()` method creates a `<font>` HTML element that causes a string to be displayed in the specified font color.
- `fontsize`: The `fontsize()` method creates a `<font>` HTML element that causes a string to be displayed in the specified font size.
- `for`: The `Symbol.for(key)` method searches for existing symbols in a runtime-wide symbol registry with the given key and returns it if found. Otherwise a new symbol gets created in the global symbol registry with this key.
- `forEach`: The `forEach()` method executes a provided function once for each value in the `Set` object, in insertion order.
- `forEach`: The `forEach()` method executes a provided function once for each array element.
- `forEach`: The `forEach()` method executes a provided function once per array element. This method has the same algorithm as `Array.prototype.forEach()`. TypedArray is one of the typed array types here.
- `forEach`: The `forEach()` method executes a provided function once per each key/value pair in the `Map` object, in insertion order.
- `format`: The `Intl.RelativeTimeFormat.prototype.format()` method formats a `value` and `unit` according to the locale and formatting options of this `RelativeTimeFormat` object.
- `format`: The `Intl.NumberFormat.prototype.format()` method formats a number according to the locale and formatting options of this `NumberFormat` object.
- `format`: The `Intl.DateTimeFormat.prototype.format()` method formats a date according to the locale and formatting options of this `Intl.DateTimeFormat` object.
- `formatToParts`: The `Intl.RelativeTimeFormat.prototype.formatToParts()` method returns an `Array` of objects representing the relative time format in parts that can be used for custom locale-aware formatting.
- `formatToParts`: The `Intl.Numberformat.prototype.formatToParts()` method allows locale-aware formatting of strings produced by `NumberTimeFormat` formatters.
- `formatToParts`: The `Intl.DateTimeFormat.prototype.formatToParts()` method allows locale-aware formatting of strings produced by `DateTimeFormat` formatters.
- `freeze`: The `Object.freeze()` method freezes an object. A frozen object can no longer be changed; freezing an object prevents new properties from being added to it, existing properties from being removed, prevents changing the enumerability, configurability, or writability of existing properties, and prevents the values of existing properties from being changed. In addition, freezing an object also prevents its prototype from being changed. `freeze()` returns the same object that was passed in.
- `from`: The `TypedArray.from()` method creates a new typed array from an array-like or iterable object. This method is nearly the same as `Array.from()`.
- `from`: The `Array.from()` method creates a new, shallow-copied `Array` instance from an array-like or iterable object.
- `fromCharCode`: The static `String.fromCharCode()` method returns a string created from the specified sequence of UTF-16 code units.
- `fromCodePoint`: The static `String.fromCodePoint()` method returns a string created by using the specified sequence of code points.
- `fromEntries`: The `Object.fromEntries()` method transforms a list of key-value pairs into an object.
- `fround`: The `Math.fround()` function returns the nearest 32-bit single precision float representation of a `Number`.

## G

- `get`: The `get()` method returns a specified element from a `Map` object.
- `get`: The `handler.get()` method is a trap for getting a property value.
- `get`: The `get()` prototype method of the `WebAssembly.Table()` object retrieves a function reference stored at a given index.
- `get`: The `get()` method returns a specified element from a `WeakMap` object.
- `get`: The static `Reflect.get()` method works like getting a property from an object (`target[propertyKey]`) as a function.
- `get Array[@@species]`: The `Array[@@species]` accessor property returns the `Array` constructor.
- `getCanonicalLocales`: The `Intl.getCanonicalLocales()` method returns an array containing the canonical locale names. Duplicates will be omitted and elements will be validated as structurally valid language tags.
- `getDate`: The `getDate()` method returns the day of the month for the specified date according to local time.
- `getDay`: The `getDay()` method returns the day of the week for the specified date according to local time, where 0 represents Sunday. For the day of the month see getDate().
- `getFloat32`: The `getFloat32()` method gets a signed 32-bit float (float) at the specified byte offset from the start of the `DataView`.
- `getFloat64`: The `getFloat64()` method gets a signed 64-bit float (double) at the specified byte offset from the start of the `DataView`.
- `getFullYear`: The `getFullYear()` method returns the year of the specified date according to local time.
- `getHours`: The `getHours()` method returns the hour for the specified date, according to local time.
- `getInt16`: The `getInt16()` method gets a signed 16-bit integer (short) at the specified byte offset from the start of the `DataView`.
- `getInt32`: The `getInt32()` method gets a signed 32-bit integer (long) at the specified byte offset from the start of the `DataView`.
- `getInt8`: The `getInt8()` method gets a signed 8-bit integer (byte) at the specified byte offset from the start of the `DataView`.
- `getItem`: The `VBArray.getItem` method returns the item at the specified location.
- `getMilliseconds`: The `getMilliseconds()` method returns the milliseconds in the specified date according to local time.
- `getMinutes`: The `getMinutes()` method returns the minutes in the specified date according to local time.
- `getMonth`: The `getMonth()` method returns the month in the specified date according to local time, as a zero-based value (where zero indicates the first month of the year).
- `getNotifier`: The `Object.getNotifer()` method was used to create an object that allows to synthetically trigger a change, but has been deprecated and removed in browsers.
- `getOwnPropertyDescriptor`: The `Object.getOwnPropertyDescriptor()` method returns a property descriptor for an own property (that is, one directly present on an object and not in the object's prototype chain) of a given object.
- `getOwnPropertyDescriptor`: The static `Reflect``.getOwnPropertyDescriptor()` method is similar to `Object.getOwnPropertyDescriptor()`. It returns a property descriptor of the given property if it exists on the object, `undefined` otherwise.
- `getOwnPropertyDescriptor`: The `handler.getOwnPropertyDescriptor()` method is a trap for `Object.getOwnPropertyDescriptor()`.
- `getOwnPropertyDescriptors`: The `Object.getOwnPropertyDescriptors()` method returns all own property descriptors of a given object.
- `getOwnPropertyNames`: The `Object.getOwnPropertyNames()` method returns an array of all properties (including non-enumerable properties except for those which use Symbol) found directly in a given object.
- `getOwnPropertySymbols`: The `Object.getOwnPropertySymbols()` method returns an array of all symbol properties found directly upon a given object.
- `getPrototypeOf`: The static `Reflect``.getPrototypeOf()` method is almost the same method as `Object.getPrototypeOf()`. It returns the prototype (i.e. the value of the internal `[[Prototype]]` property) of the specified object.
- `getPrototypeOf`: The `handler.getPrototypeOf()` method is a trap for the `[[GetPrototypeOf]]` internal method.
- `getPrototypeOf`: The `Object.getPrototypeOf()` method returns the prototype (i.e. the value of the internal `[[Prototype]]` property) of the specified object.
- `getSeconds`: The `getSeconds()` method returns the seconds in the specified date according to local time.
- `getTime`: The `getTime()` method returns the number of milliseconds* since the Unix Epoch.
- `getTimezoneOffset`: The `getTimezoneOffset()` method returns the time zone difference, in minutes, from current locale (host system settings) to UTC.
- `getUTCDate`: The `getUTCDate()` method returns the day (date) of the month in the specified date according to universal time.
- `getUTCDay`: The `getUTCDay()` method returns the day of the week in the specified date according to universal time, where 0 represents Sunday.
- `getUTCFullYear`: The `getUTCFullYear()` method returns the year in the specified date according to universal time.
- `getUTCHours`: The `getUTCHours()` method returns the hours in the specified date according to universal time.
- `getUTCMilliseconds`: The `getUTCMilliseconds()` method returns the milliseconds in the specified date according to universal time.
- `getUTCMinutes`: The `getUTCMinutes()` method returns the minutes in the specified date according to universal time.
- `getUTCMonth`: The `getUTCMonth()` returns the month of the specified date according to universal time, as a zero-based value (where zero indicates the first month of the year).
- `getUTCSeconds`: The `getUTCSeconds()` method returns the seconds in the specified date according to universal time.
- `getUint16`: The `getUint16()` method gets an unsigned 16-bit integer (unsigned short) at the specified byte offset from the start of the `DataView`.
- `getUint32`: The `getUint32()` method gets an unsigned 32-bit integer (unsigned long) at the specified byte offset from the start of the `DataView`.
- `getUint8`: The `getUint8()` method gets an unsigned 8-bit integer (unsigned byte) at the specified byte offset from the start of the `DataView`.
- `getVarDate`: The `getVarDate` method returns a `VT_DATE` value from a `Date` object.
- `getYear`: The `getYear()` method returns the year in the specified date according to local time. Because `getYear()` does not return full years ("year 2000 problem"), it is no longer used and has been replaced by the `getFullYear()` method.
- `grow`: The `grow()` protoype method of the `Memory` object increases the size of the memory instance by a specified number of WebAssembly pages.
- `grow`: The `grow()` prototype method of the `WebAssembly.Table` object increases the size of the Table instance by a specified number of elements.

## H

- `has`: The `has()` method returns a boolean indicating whether an element with the specified key exists or not.
- `has`: The `handler.has()` method is a trap for the `in` operator.
- `has`: The static `Reflect``.has()` method works like the `in` operator as a function.
- `has`: The `has()` method returns a boolean indicating whether an element with the specified value exists in a `Set` object or not.
- `has`: The `has()` method returns a boolean indicating whether an element with the specified key exists in the `WeakMap` object or not.
- `has`: The `has()` method returns a boolean indicating whether an object exists in a `WeakSet` or not.
- `hasOwnProperty`: The `hasOwnProperty()` method returns a boolean indicating whether the object has the specified property as its own property (as opposed to inheriting it).
- `hypot`: The `Math.hypot()` function returns the square root of the sum of squares of its arguments, that is:

## I

- `Indexed collections`: This chapter introduces collections of data which are ordered by an index value. This includes arrays and array-like constructs such as `Array` objects and `TypedArray` objects.
- `imports`: The `WebAssembly.imports()` function returns an array containing descriptions of all the declared imports of the given `Module`.
- `imul`: The `Math.imul()` function returns the result of the C-like 32-bit multiplication of the two parameters.
- `includes`: The `includes()` method determines whether one string may be found within another string, returning `true` or `false` as appropriate.
- `includes`: The `includes()` method determines whether a typed array includes a certain element, returning `true` or `false` as appropriate. This method has the same algorithm as `Array.prototype.includes()`. TypedArray is one of the typed array types here.
- `includes`: The `includes()` method determines whether an array includes a certain value among its entries, returning `true` or `false` as appropriate.
- `indexOf`: The `indexOf()` method returns the first index at which a given element can be found in the typed array, or -1 if it is not present. This method has the same algorithm as `Array.prototype.indexOf()`. TypedArray is one of the typed array types here.
- `indexOf`: The `indexOf()` method returns the index within the calling `String` object of the first occurrence of the specified value, starting the search at `fromIndex`. Returns -1 if the value is not found.
- `indexOf`: The `indexOf()` method returns the first index at which a given element can be found in the array, or -1 if it is not present.
- `instantiate`: The `WebAssembly.instantiate()` function allows you to compile and instantiate WebAssembly code. This function has two overloads:
- `instantiateStreaming`: The `WebAssembly.instantiateStreaming()` function compiles and instantiates a WebAssembly module directly from a streamed underlying source. This is the most efficient, optimized way to load wasm code.
- `is`: The `Object.is()` method determines whether two values are the same value.
- `isArray`: The `Array.isArray()` method determines whether the passed value is an `Array`.
- `isExtensible`: The `Object.isExtensible()` method determines if an object is extensible (whether it can have new properties added to it).
- `isExtensible`: The static `Reflect``.isExtensible()` method determines if an object is extensible (whether it can have new properties added to it). It is similar to `Object.isExtensible()`, but with some differences.
- `isExtensible`: The `handler.isExtensible()` method is a trap for `Object.isExtensible()`.
- `isFinite`: The `Number.isFinite()` method determines whether the passed value is a finite number.
- `isFrozen`: The `Object.isFrozen()` determines if an object is frozen.
- `isGenerator`: The non-standard `isGenerator()` method used to determine whether or not a function is a generator. It has been removed from Firefox starting with version 58.
- `isInteger`: The `Number.isInteger()` method determines whether the passed value is an integer.
- `isLockFree`: The static `Atomics``.isLockFree()` method is used to determine whether to use locks or atomic operations. It returns `true`, if the given size is one of the BYTES_PER_ELEMENT property of integer TypedArray types.
- `isNaN`: The `isNaN()` function determines whether a value is `NaN` or not. Note: coercion inside the `isNaN` function has interesting rules; you may alternatively want to use `Number.isNaN()`, as defined in ECMAScript 2015.
- `isNaN`: The `Number.isNaN()` method determines whether the passed value is `NaN` and its type is `Number`. It is a more robust version of the original, global `isNaN()`.
- `isPrototypeOf`: The `isPrototypeOf()` method checks if an object exists in another object's prototype chain.
- `isSafeInteger`: The `Number.isSafeInteger()` method determines whether the provided value is a number that is a safe integer.
- `isSealed`: The `Object.isSealed()` method determines if an object is sealed.
- `isView`: The `ArrayBuffer.isView()` method returns `true` if `arg` is one of the `ArrayBuffer` views, such as typed array objects or a `DataView`; `false` otherwise.
- `italics`: The `italics()` method creates an `<i>` HTML element that causes a string to be italic.
- `item`: The `Enumerator.item` method returns the current item in the collection.

## J

- `join`: The `join()` method creates and returns a new string by concatenating all of the elements in an array (or an array-like object), separated by commas or a specified separator string. If the array has only one item, then that item will be returned without using the separator.
- `join`: The `join()` method joins all elements of an array into a string. This method has the same algorithm as `Array.prototype.join()`. TypedArray is one of the typed array types here.

## K

- `keyFor`: The `Symbol.keyFor(sym)` method retrieves a shared symbol key from the global symbol registry for the given symbol.
- `keys`: The `keys()` method returns a new `Array Iterator` object that contains the keys for each index in the array.
- `keys`: The `keys()` method returns a new `Iterator` object that contains the keys for each element in the `Map` object in insertion order.
- `keys`: The `Object.keys()` method returns an array of a given object's own property `names`, in the same order as we get with a normal loop.
- `keys`: The `keys()` method returns a new `Array Iterator` object that contains the keys for each index in the array.

## L

- `lastIndexOf`: The `lastIndexOf()` method returns the last index at which a given element can be found in the array, or -1 if it is not present. The array is searched backwards, starting at `fromIndex`.
- `lastIndexOf`: The `lastIndexOf()` method returns the last index at which a given element can be found in the typed array, or -1 if it is not present. The typed array is searched backwards, starting at `fromIndex`. This method has the same algorithm as `Array.prototype.lastIndexOf()`. TypedArray is one of the typed array types here.
- `lastIndexOf`: The `lastIndexOf()` method returns the index within the calling `String` object of the last occurrence of the specified value, searching backwards from `fromIndex`. Returns -1 if the value is not found.
- `lbound`: The VBArray.lbound method returns the lowest index value used in the specified dimension of a VBArray.
- `link`: The `link()` method creates a string representing the code for an `<a>` HTML element to be used as a hypertext link to another URL.
- `load`: The static `Atomics``.load()` method returns a value at a given position in the array.
- `localeCompare`: The `localeCompare()` method returns a number indicating whether a reference string comes before or after or is the same as the given string in sort order.
- `log`: The `Math.log()` function returns the natural logarithm (base `e`) of a number, that is
- `log10`: The `Math.log10()` function returns the base 10 logarithm of a number, that is
- `log1p`: The `Math.log1p()` function returns the natural logarithm (base `e`) of 1 + a number, that is
- `log2`: The `Math.log2()` function returns the base 2 logarithm of a number, that is

## M

- `map`: The `map()` method creates a new array with the results of calling a provided function on every element in the calling array.
- `map`: The `map()` method creates a new typed array with the results of calling a provided function on every element in this typed array. This method has the same algorithm as `Array.prototype.map()`. TypedArray is one of the typed array types here.
- `match`: The `match()` method retrieves the result of matching a string against a regular expression.
- `matchAll`: The `matchAll()` method returns an iterator of all results matching a string against a regular expression, including capturing groups.
- `max`: The `Math.max()` function returns the largest of zero or more numbers.
- `min`: The static function `Math.min()` returns the lowest-valued number passed into it, or `NaN` if any parameter isn't a number and can't be converted into one.
- `move`: The `move()` method used to copy the sequence of array elements within the array to the position starting at `target`. However, this non-standard method has been replaced with the standard `TypedArray.prototype.copyWithin()` method. TypedArray is one of the typed array types here.
- `moveFirst`: The Enumerator.moveFirst method resets the current item in the collection to the first item.
- `moveNext`: The `Enumerator.moveNext` method moves the current item to the next item in the collection.
- `msTraceAsyncCallbackCompleted`: The `debug.msTraceAsyncCallbackCompleted` function indicates that an asynchronous operation has completed.
- `msTraceAsyncCallbackStarting`: The `debug.msTraceAsyncCallbackStarting` function associates the callback stack with a previously specified asynchronous operation.
- `msTraceAsyncOperationStarting`: Initiates a trace for an asynchronous operation.
- `msUpdateAsyncCallbackRelation`: The `debug.msUpdateAsyncCallbackRelation` function updates the relationship status between a synchronous work item and the associated asynchronous operation.

## N

- `next`: The `next``()` method returns an object with two properties `done` and `value`. You can also provide a parameter to the `next` method to send a value to the generator.
- `normalize`: The `normalize()` method returns the Unicode Normalization Form of a given string (if the value isn't a string, it will be converted to one first).
- `notify`: The static `Atomics``.notify()` method notifies up some agents that are sleeping in the wait queue.
- `now`: The `Date.now()` method returns the number of milliseconds elapsed since January 1, 1970 00:00:00 UTC.

## O

- `observe`: The `Array.observe()` method was used for asynchronously observing changes to Arrays, similar to `Object.observe()` for objects. It provided a stream of changes in order of occurrence. It's equivalent to `Object.observe()` invoked with the accept type list `["add", "update", "delete", "splice"]`. However, this API has been deprecated and removed from Browsers. You can use the more general `Proxy` object instead.
- `observe`: The `Object.observe()` method was used for asynchronously observing the changes to an object. It provided a stream of changes in the order in which they occur. However, this API has been deprecated and removed from browsers. You can use the more general `Proxy` object instead.
- `of`: The `Array.of()` method creates a new `Array` instance from a variable number of arguments, regardless of number or type of the arguments.
- `of`: The `TypedArray.of()` method creates a new typed array from a variable number of arguments. This method is nearly the same as `Array.of()`.
- `or`: The static `Atomics``.or()` method computes a bitwise OR with a given value at a given position in the array, and returns the old value at that position. This atomic operation guarantees that no other write happens until the modified value is written back.
- `ownKeys`: The `handler.ownKeys()` method is a trap for `Reflect.ownKeys()`.
- `ownKeys`: The static `Reflect``.ownKeys()` method returns an array of the `target` object's own property keys.

## P

- `padEnd`: The `padEnd()` method pads the current string with a given string (repeated, if needed) so that the resulting string reaches a given length. The padding is applied from the end (right) of the current string.
- `padStart`: The `padStart()` method pads the current string with another string (multiple times, if needed) until the resulting string reaches the given length.
- `parse`: The `Date.parse()` method parses a string representation of a date, and returns the number of milliseconds since January 1, 1970, 00:00:00 UTC or `NaN` if the string is unrecognized or, in some cases, contains illegal date values (e.g. 2015-02-31).
- `parse`: The `JSON.parse()` method parses a JSON string, constructing the JavaScript value or object described by the string. An optional reviver function can be provided to perform a transformation on the resulting object before it is returned.
- `parse: bad parsing`: `SyntaxError`
- `parseFloat`: The `Number.parseFloat()` method parses a string argument and returns a floating point number.
- `parseInt`: The `Number.parseInt()` method parses a string argument and returns an integer of the specified radix or base.
- `pop`: The `pop()` method removes the last element from an array and returns that element. This method changes the length of the array.
- `pow`: The `Math.pow()` function returns the `base` to the `exponent` power, that is, `baseexponent`.
- `preventExtensions`: The static `Reflect``.preventExtensions()` method prevents new properties from ever being added to an object (i.e. prevents future extensions to the object). It is similar to `Object.preventExtensions()`, but with some differences.
- `preventExtensions`: The `handler.preventExtensions()` method is a trap for `Object.preventExtensions()`.
- `preventExtensions`: The `Object.preventExtensions()` method prevents new properties from ever being added to an object (i.e. prevents future extensions to the object).
- `propertyIsEnumerable`: The `propertyIsEnumerable()` method returns a Boolean indicating whether the specified property is enumerable.
- `prototype[@@iterator]`: The initial value of the @@iterator property is the same function object as the initial value of the `values` property.
- `prototype[@@iterator]`: The `[@@iterator]()` method returns a new `Iterator` object that iterates over the code points of a String value, returning each code point as a String value.
- `prototype[@@iterator]`: The initial value of the `@@iterator` property is the same function object as the initial value of the `values()` property.
- `prototype[@@iterator]`: The initial value of the `@@iterator` property is the same function object as the initial value of the `values` property.
- `prototype[@@iterator]`: The initial value of the `@@iterator` property is the same function object as the initial value of the `entries` method.
- `prototype[@@matchAll]`: The `[@@matchAll]` method returns all matches of the regular expression against a string.
- `prototype[@@match]`: The `[@@match]()` method retrieves the matches when matching a string against a regular expression.
- `prototype[@@replace]`: The `[@@replace]()` method replaces some or all matches of a `this` pattern in a string by a `replacement`, and returns the result of the replacement as a new string. The `replacement` can be a string or a function to be called for each match.
- `prototype[@@search]`: The `[@@search]()` method executes a search for a match between a `this` regular expression and a string.
- `prototype[@@split]`: The `[@@split]()` method splits a `String` object into an array of strings by separating the string into substrings.
- `prototype[@@toPrimitive]`: The `[@@toPrimitive]()` method converts a `Date` object to a primitive value.
- `prototype[@@toPrimitive]`: The `[@@toPrimitive]()` method converts a Symbol object to a primitive value.
- `push`: The `push()` method adds one or more elements to the end of an array and returns the new length of the array.

## Q

- `quote`: The non-standard `quote()` method returns a copy of the string, replacing various special characters in the string with their escape sequences and wrapping the result in double-quotes (`"`).

## R

- `race`: The `Promise.race()` method returns a promise that resolves or rejects as soon as one of the promises in an iterable resolves or rejects, with the value or reason from that promise.
- `random`: The `Math.random()` function returns a floating-point, pseudo-random number in the range 0–1 (inclusive of 0, but not 1) with approximately uniform distribution over that range — which you can then scale to your desired range. The implementation selects the initial seed to the random number generation algorithm; it cannot be chosen or reset by the user.
- `raw`: The static `String.raw()` method is a tag function of template literals, similar to the `r` prefix in Python or the `@` prefix in C# for string literals (yet there is a difference: see explanations in this issue). It's used to get the raw string form of template strings, that is, substitutions (e.g. ${foo}) are processed, but escapes (e.g. `\n`) are not.
- `reduce`: The `reduce()` method executes a reducer function (that you provide) on each member of the array resulting in a single output value.
- `reduce`: The `reduce()` method applies a function against an accumulator and each value of the typed array (from left-to-right) has to reduce it to a single value. This method has the same algorithm as `Array.prototype.reduce()`. TypedArray is one of the typed array types here.
- `reduceRight`: The `reduceRight()` method applies a function against an accumulator and each value of the array (from right-to-left) to reduce it to a single value.
- `reduceRight`: The `reduceRight()` method applies a function against an accumulator and each value of the typed array (from right-to-left) has to reduce it to a single value. This method has the same algorithm as `Array.prototype.reduceRight()`. TypedArray is one of the typed array types here.
- `reject`: The `Promise.reject()` method returns a `Promise` object that is rejected with a given reason.
- `repeat`: The `repeat()` method constructs and returns a new string which contains the specified number of copies of the string on which it was called, concatenated together.
- `replace`: The `replace()` method returns a new string with some or all matches of a `pattern` replaced by a `replacement`.
- `resolve`: The `Promise.resolve()` method returns a `Promise` object that is resolved with a given value. If the value is a promise, that promise is returned; if the value is a thenable (i.e. has a `"then" method`), the returned promise will "follow" that thenable, adopting its eventual state; otherwise the returned promise will be fulfilled with the value. This function flattens nested layers of promise-like objects (e.g. a promise that resolves to a promise that resolves to something) into a single layer.
- `resolvedOptions`: The `Intl.RelativeTimeFormat.prototype.resolvedOptions()` method returns a new object with properties reflecting the locale and relative time formatting options computed during initialization of this `RelativeTimeFormat` object.
- `resolvedOptions`: The `Intl.DateTimeFormat.prototype.resolvedOptions()` method returns a new object with properties reflecting the locale and date and time formatting options computed during initialization of this `DateTimeFormat` object.
- `resolvedOptions`: The `Intl.NumberFormat.prototype.resolvedOptions()` method returns a new object with properties reflecting the locale and number formatting options computed during initialization of this `NumberFormat` object.
- `resolvedOptions`: The `Intl.Collator.prototype.resolvedOptions()` method returns a new object with properties reflecting the locale and collation options computed during initialization of this `Collator` object.
- `resolvedOptions`: The `Intl.PluralRules.prototype.resolvedOptions()` method returns a new object with properties reflecting the locale and plural formatting options computed during initialization of this `PluralRules` object.
- `return`: The `return()` method returns the given value and finishes the generator.
- `reverse`: The `reverse()` method reverses a typed array in place. The first typed array element becomes the last and the last becomes the first. This method has the same algorithm as `Array.prototype.reverse()`. TypedArray is one of the typed array types here.
- `reverse`: The `reverse()` method reverses an array in place. The first array element becomes the last, and the last array element becomes the first.
- `revocable`: The `Proxy.revocable()` method is used to create a revocable `Proxy` object.
- `round`: The `Math.round()` function returns the value of a number rounded to the nearest integer.

## S

- `ScriptEngine`: The `ScriptEngine` function gets the name of the scripting language in use.
- `ScriptEngineBuildVersion`: The `ScriptEngineBuildVersion` function bets the build version number of the scripting engine in use.
- `ScriptEngineMajorVersion`: The `ScriptEngineMajorVersion` function gets the major version number of the scripting engine in use.
- `ScriptEngineMinorVersion`: The `ScriptEngineMinorVersion` function gets the minor version number of the scripting engine in use.
- `seal`: The `Object.seal()` method seals an object, preventing new properties from being added to it and marking all existing properties as non-configurable. Values of present properties can still be changed as long as they are writable.
- `search`: The `search()` method executes a search for a match between a regular expression and this `String` object.
- `select`: The `Intl.PluralRules.prototype.select` method returns a String indicating which plural rule to use for locale-aware formatting.
- `set`: The `set()` method adds or updates an element with a specified key and a value to a `Map` object.
- `set`: The `handler.set()` method is a trap for setting a property value.
- `set`: The static `Reflect``.set()` method works like setting a property on an object.
- `set`: The `set()` method stores multiple values in the typed array, reading input values from a specified array.
- `set`: The `set()` method adds a new element with a specified `key` and `value` to a `WeakMap` object.
- `set`: The `set()` prototype method of the `WebAssembly.Table` object mutates a reference stored at a given index to a different value.
- `setDate`: The `setDate()` method sets the day of the `Date` object relative to the beginning of the currently set month.
- `setFloat32`: The `setFloat32()` method stores a signed 32-bit float (float) value at the specified byte offset from the start of the `DataView`.
- `setFloat64`: The `setFloat64()` method stores a signed 64-bit float (double) value at the specified byte offset from the start of the `DataView`.
- `setFullYear`: The `setFullYear()` method sets the full year for a specified date according to local time. Returns new timestamp.
- `setHours`: The `setHours()` method sets the hours for a specified date according to local time, and returns the number of milliseconds since January 1, 1970 00:00:00 UTC until the time represented by the updated `Date` instance.
- `setInt16`: The `setInt16()` method stores a signed 16-bit integer (short) value at the specified byte offset from the start of the `DataView`.
- `setInt32`: The `setInt32()` method stores a signed 32-bit integer (long) value at the specified byte offset from the start of the `DataView`.
- `setInt8`: The `setInt8()` method stores a signed 8-bit integer (byte) value at the specified byte offset from the start of the `DataView`.
- `setMilliseconds`: The `setMilliseconds()` method sets the milliseconds for a specified date according to local time.
- `setMinutes`: The `setMinutes()` method sets the minutes for a specified date according to local time.
- `setMonth`: The `setMonth()` method sets the month for a specified date according to the currently set year.
- `setPrototypeOf`: The `Object.setPrototypeOf()` method sets the prototype (i.e., the internal `[[Prototype]]` property) of a specified object to another object or `null`.
- `setPrototypeOf`: The `handler.setPrototypeOf()` method is a trap for `Object.setPrototypeOf()`.
- `setPrototypeOf`: The static `Reflect``.setPrototypeOf()` method is the same method as `Object.setPrototypeOf()`. It sets the prototype (i.e., the internal `[[Prototype]]` property) of a specified object to another object or to `null`.
- `setSeconds`: The `setSeconds()` method sets the seconds for a specified date according to local time.
- `setTime`: The `setTime()` method sets the `Date` object to the time represented by a number of milliseconds since January 1, 1970, 00:00:00 UTC.
- `setUTCDate`: The `setUTCDate()` method sets the day of the month for a specified date according to universal time.
- `setUTCFullYear`: The `setUTCFullYear()` method sets the full year for a specified date according to universal time.
- `setUTCHours`: The `setUTCHours()` method sets the hour for a specified date according to universal time, and returns the number of milliseconds since January 1, 1970 00:00:00 UTC until the time represented by the updated `Date` instance.
- `setUTCMilliseconds`: The `setUTCMilliseconds()` method sets the milliseconds for a specified date according to universal time.
- `setUTCMinutes`: The `setUTCMinutes()` method sets the minutes for a specified date according to universal time.
- `setUTCMonth`: The `setUTCMonth()` method sets the month for a specified date according to universal time.
- `setUTCSeconds`: The `setUTCSeconds()` method sets the seconds for a specified date according to universal time.
- `setUint16`: The `setUint16()` method stores an unsigned 16-bit integer (unsigned short) value at the specified byte offset from the start of the `DataView`.
- `setUint32`: The `setUint32()` method stores an unsigned 32-bit integer (unsigned long) value at the specified byte offset from the start of the `DataView`.
- `setUint8`: The `setUint8()` method stores an unsigned 8-bit integer (byte) value at the specified byte offset from the start of the `DataView`.
- `setYear`: The `setYear()` method sets the year for a specified date according to local time. Because `setYear()` does not set full years ("year 2000 problem"), it is no longer used and has been replaced by the `setFullYear()` method.
- `shift`: The `shift()` method removes the first element from an array and returns that removed element. This method changes the length of the array.
- `sign`: The `Math.sign()` function returns the sign of a number, indicating whether the number is positive, negative or zero.
- `sin`: The `Math.sin()` function returns the sine of a number.
- `sinh`: The `Math.sinh()` function returns the hyperbolic sine of a number, that can be expressed using the constant e:
- `slice`: The `slice()` method extracts a section of a string and returns it as a new string, without modifying the original string.
- `slice`: The `slice()` method returns a new `ArrayBuffer` whose contents are a copy of this `ArrayBuffer`'s bytes from `begin`, inclusive, up to `end`, exclusive.
- `slice`: The `slice()` method returns a shallow copy of a portion of a typed array into a new typed array object. This method has the same algorithm as `Array.prototype.slice()`. TypedArray is one of the typed array types here.
- `slice`: The `slice()` method returns a shallow copy of a portion of an array into a new array object selected from `begin` to `end` (`end` not included). The original array will not be modified.
- `slice`: The `SharedArrayBuffer.prototype.slice()` method returns a new `SharedArrayBuffer` whose contents are a copy of `this SharedArrayBuffer`'s bytes from begin, inclusive, up to end, exclusive. If either begin or end is negative, it refers to an index from the end of the array, as opposed to from the beginning. This method has the same algorithm as `Array.prototype.slice()`.
- `small`: The `small()` method creates a `<small>` HTML element that causes a string to be displayed in a small font.
- `some`: The `some()` method tests whether at least one element in the array passes the test implemented by the provided function.
- `some`: The `some()` method tests whether some element in the typed array passes the test implemented by the provided function. This method has the same algorithm as `Array.prototype.some()`. TypedArray is one of the typed array types here.
- `sort`: The `sort()` method sorts the elements of an array in place and returns the array. The default sort order is built upon converting the elements into strings, then comparing their sequences of UTF-16 code units values.
- `sort`: The `sort()` method sorts the elements of a typed array numerically in place and returns the typed array. This method has the same algorithm as `Array.prototype.sort()`, except that sorts the values numerically instead of as strings. TypedArray is one of the typed array types here.
- `splice`: The `splice()` method changes the contents of an array by removing or replacing existing elements and/or adding new elements in place.
- `split`: The `split()` method splits a `String` object into an array of strings by separating the string into substrings, using a specified separator string to determine where to make each split.
- `sqrt`: The `Math.sqrt()` function returns the square root of a number, that is
- `startsWith`: The `startsWith()` method determines whether a string begins with the characters of a specified string, returning `true` or `false` as appropriate.
- `store`: The static `Atomics``.store()` method stores a given value at the given position in the array and returns that value.
- `strike`: The `strike()` method creates a `<strike>` HTML element that causes a string to be displayed as struck-out text.
- `stringify`: The `JSON.stringify()` method converts a JavaScript object or value to a JSON string, optionally replacing values if a replacer function is specified or optionally including only the specified properties if a replacer array is specified.
- `sub`: The static `Atomics``.sub()` method substracts a given value at a given position in the array and returns the old value at that position. This atomic operation guarantees that no other write happens until the modified value is written back.
- `sub`: The `sub()` method creates a `<sub>` HTML element that causes a string to be displayed as subscript.
- `subarray`: The `subarray()` method returns a new TypedArray on the same `ArrayBuffer` store and with the same element types as for this TypedArray object. The `begin` offset is inclusive and the `end` offset is exclusive. TypedArray is one of the typed array types.
- `substr`: The `substr()` method returns a portion of the string, starting at the specified index and extending for a given number of characters afterward.
- `substring`: The `substring()` method returns the part of the `string` between the start and end indexes, or to the end of the string.
- `sup`: The `sup()` method creates a `<sup>` HTML element that causes a string to be displayed as superscript.
- `supportedLocalesOf`: The `Intl.NumberFormat.supportedLocalesOf()` method returns an array containing those of the provided locales that are supported in number formatting without having to fall back to the runtime's default locale.
- `supportedLocalesOf`: The `Intl.DateTimeFormat.supportedLocalesOf()` method returns an array containing those of the provided locales that are supported in date and time formatting without having to fall back to the runtime's default locale.
- `supportedLocalesOf`: The `Intl.Collator.supportedLocalesOf()` method returns an array containing those of the provided locales that are supported in collation without having to fall back to the runtime's default locale.
- `supportedLocalesOf`: The `Intl.PluralRules.supportedLocalesOf()` method returns an array containing those of the provided locales that are supported in plural formatting without having to fall back to the runtime's default locale.
- `supportedLocalesOf`: The `Intl.RelativeTimeFormat.supportedLocalesOf()` method returns an array containing those of the provided locales that are supported in date and time formatting without having to fall back to the runtime's default locale.
- `supportedLocalesOf`: The `Intl.ListFormat.supportedLocalesOf()` method returns an array containing those of the provided locales that are supported in date and time formatting without having to fall back to the runtime's default locale.

## T

- `tan`: The `Math.tan()` function returns the tangent of a number.
- `tanh`: The `Math.tanh()` function returns the hyperbolic tangent of a number, that is
- `test`: The `test()` method executes a search for a match between a regular expression and a specified string. Returns `true` or `false`.
- `then`: The `then()` method returns a `Promise`. It takes up to two arguments: callback functions for the success and failure cases of the `Promise`.
- `throw`: The `throw()` method resumes the execution of a generator by throwing an error into it and returns an object with two properties `done` and `value`.
- `toArray`: The `VBArray.toArray` method returns a standard JavaScript array converted from a VBArray.
- `toDateString`: The `toDateString()` method returns the date portion of a `Date` object in human readable form in American English.
- `toExponential`: The `toExponential()` method returns a string representing the Number object in exponential notation.
- `toFixed`: The `toFixed()` method formats a number using fixed-point notation.
- `toGMTString`: The `toGMTString()` method converts a date to a string, using Internet Greenwich Mean Time (GMT) conventions. The exact format of the value returned by `toGMTString()` varies according to the platform and browser, in general it should represent a human readable date string.
- `toISOString`: The `toISOString()` method returns a string in simplified extended ISO format (ISO 8601), which is always 24 or 27 characters long (`YYYY-MM-DDTHH:mm:ss.sssZ` or `±YYYYYY-MM-DDTHH:mm:ss.sssZ`, respectively). The timezone is always zero UTC offset, as denoted by the suffix "`Z`".
- `toInteger`: The `Number.toInteger()` method used to evaluate the passed value and convert it to an integer, but its implementation has been removed.
- `toJSON`: The `toJSON()` method returns a string representation of the `Date` object.
- `toLocaleDateString`: The `toLocaleDateString()` method returns a string with a language sensitive representation of the date portion of this date. The new `locales` and `options` arguments let applications specify the language whose formatting conventions should be used and allow to customize the behavior of the function. In older implementations, which ignore the `locales` and `options` arguments, the locale used and the form of the string returned are entirely implementation dependent.
- `toLocaleFormat`: The non-standard `toLocaleFormat()` method converts a date to a string using the specified formatting. `Intl.DateTimeFormat` is an alternative to format dates in a standards-compliant way. See also the newer version of `Date.prototype.toLocaleDateString()`.
- `toLocaleLowerCase`: The `toLocaleLowerCase()` method returns the calling string value converted to lower case, according to any locale-specific case mappings.
- `toLocaleString`: The `toLocaleString()` method returns a string with a language sensitive representation of this date. The new `locales` and `options` arguments let applications specify the language whose formatting conventions should be used and customize the behavior of the function. In older implementations, which ignore the `locales` and `options` arguments, the locale used and the form of the string returned are entirely implementation dependent.
- `toLocaleString`: The `toLocaleString()` method returns a string representing the elements of the typed array. The elements are converted to strings and are separated by a locale-specific string (such as a comma “,”). This method has the same algorithm as `Array.prototype.toLocaleString()` and, as the typed array elements are numbers, the same algorithm as `Number.prototype.toLocaleString()` applies for each element. TypedArray is one of the typed array types here.
- `toLocaleString`: The `toLocaleString()` method returns a string with a language-sensitive representation of this number.
- `toLocaleString`: The `toLocaleString()` method returns a string representing the elements of the array. The elements are converted to Strings using their `toLocaleString` methods and these Strings are separated by a locale-specific String (such as a comma “,”).
- `toLocaleString`: The `toLocaleString()` method returns a string representing the object. This method is meant to be overridden by derived objects for locale-specific purposes.
- `toLocaleTimeString`: The `toLocaleTimeString()` method returns a string with a language sensitive representation of the time portion of this date. The new `locales` and `options` arguments let applications specify the language whose formatting conventions should be used and customize the behavior of the function. In older implementations, which ignore the `locales` and `options` arguments, the locale used and the form of the string returned are entirely implementation dependent.
- `toLocaleUpperCase`: The `toLocaleUpperCase()` method returns the calling string value converted to upper case, according to any locale-specific case mappings.
- `toLowerCase`: The `toLowerCase()` method returns the calling string value converted to lower case.
- `toPrecision`: The `toPrecision()` method returns a string representing the `Number` object to the specified precision.
- `toSource`: The `toSource()` method returns a string representing the source code of the object.
- `toSource`: The `toSource()` method returns a string representing the source code of the object.
- `toSource`: The `toSource()` method returns a string representing the source code of the array.
- `toSource`: The `toSource()` method returns a string representing the source code of the object.
- `toSource`: The `toSource()` method returns a string representing the source code of the object.
- `toSource`: The `toSource()` method returns a string representing the source code of the object.
- `toSource`: The `toSource()` method returns a string representing the source code of the object.
- `toSource`: The `toSource()` method returns a string representing the source code of the object.
- `toSource`: The `toSource()` method returns code that could eval to the same error.
- `toSource`: The `toSource()` method returns a string representing the source code of the object.
- `toString`: The `toString()` method returns a string representing the specified array and its elements.
- `toString`: The `toString()` method returns a string representing the specified array and its elements. This method has the same algorithm as `Array.prototype.toString()`. TypedArray is one of the typed array types here.
- `toString`: The `toString()` method returns a string representing the source code of the function.
- `toString`: The `toString()` method returns a string representing the specified `Error` object.
- `toString`: The `toString()` method returns a string representing the regular expression.
- `toString`: The `toString()` method returns a string representing the specified `Symbol` object.
- `toString`: The `toString()` method returns a string representing the specified `Date` object.
- `toString`: The `toString()` method returns a string representing the specified Boolean object.
- `toString`: The `toString()` method returns a string representing the object.
- `toString`: The `toString()` method returns a string representing the specified object.
- `toString`: The `toString()` method returns a string representing the specified `Number` object.
- `toTimeString`: The `toTimeString()` method returns the time portion of a `Date` object in human readable form in American English.
- `toUTCString`: The `toUTCString()` method converts a date to a string, using the UTC time zone.
- `toUpperCase`: The `toUpperCase()` method returns the calling string value converted to uppercase (the value will be converted to a string if it isn't one).
- `transfer`: The static `ArrayBuffer.transfer()` method returns a new `ArrayBuffer` whose contents have been taken from the `oldBuffer`'s data and then is either truncated or zero-extended by `newByteLength`. If `newByteLength` is `undefined`, the `byteLength` of the `oldBuffer` is used. This operation leaves `oldBuffer` in a detached state.
- `trim`: The `trim()` method removes whitespace from both ends of a string. Whitespace in this context is all the whitespace characters (space, tab, no-break space, etc.) and all the line terminator characters (LF, CR, etc.).
- `trimEnd`: The `trimEnd()` method removes whitespace from the end of a string. `trimRight()` is an alias of this method.
- `trimStart`: The `trimStart()` method removes whitespace from the beginning of a string. `trimLeft()` is an alias of this method.
- `trunc`: The `Math.trunc()` function returns the integer part of a number by removing any fractional digits.

## U

- `UTC`: The `Date.UTC()` method accepts the same parameters as the `Date` constructor, but treats them as UTC. It returns the number of milliseconds since January 1, 1970, 00:00:00 UTC.
- `ubound`: The `VBArray.ubound` method returns the highest index value used in the specified dimension of the VBArray.
- `unobserve`: The Array.unobserve() method was used to remove observers set by `Array.observe()`, but has been deprecated and removed from Browsers. You can use the more general `Proxy` object instead.
- `unobserve`: The `Object.unobserve()` method was used to remove observers set by `Object.observe()`, but has been deprecated and removed from Browsers. You can use the more general `Proxy` object instead.
- `unshift`: The `unshift()` method adds one or more elements to the beginning of an array and returns the new length of the array.
- `unwatch`: The `unwatch()` method removes a watchpoint set with the `watch()` method.

## V

- `validate`: The `WebAssembly.validate()` function validates a given typed array of WebAssembly binary code, returning whether the bytes form a valid wasm module (`true`) or not (`false`).
- `valueOf`: The `valueOf()` method returns the primitive value of a `Date` object.
- `valueOf`: The `valueOf()` method returns the wrapped primitive value of a `Number` object.
- `valueOf`: The `valueOf()` method returns the primitive value of the specified object.
- `valueOf`: The `valueOf()` method returns the primitive value of a `Boolean` object.
- `valueOf`: The `valueOf()` method returns the primitive value of a `String` object.
- `valueOf`: The `valueOf()` method returns the primitive value of a Symbol object.
- `values`: The `values()` method returns a new `Iterator` object that contains the values for each element in the `Set` object in insertion order.
- `values`: The `values()` method returns a new Iterator object that contains the values for each element in the `Map` object in insertion order.
- `values`: The `values()` method returns a new `Array Iterator` object that contains the values for each index in the array.
- `values`: The `values()` method returns a new `Array Iterator` object that contains the values for each index in the array.
- `values`: The `Object.values()` method returns an array of a given object's own enumerable property values, in the same order as that provided by a `for...in` loop (the difference being that a for-in loop enumerates properties in the prototype chain as well).

## W

- `wait`: The static `Atomics``.wait()` method verifies that a given position in an `Int32Array` still contains a given value and if so sleeps, awaiting a wakeup or a timeout. It returns a string which is either `"ok"`, `"not-equal"`, or `"timed-out"`.
- `watch`: The `watch()` method watches for a property to be assigned a value and runs a function when that occurs.
- `write`: The `debug.write` function sends strings to the script debugger.
- `writeln`: The `debug.writeln` function sends strings to the script debugger, followed by a newline character.

## X

- `xor`: The static `Atomics``.xor()` method computes a bitwise XOR with a given value at a given position in the array, and returns the old value at that position. This atomic operation guarantees that no other write happens until the modified value is written back.

## Y

## Z

## _

- `__defineGetter__`: The `__defineGetter__` method binds an object's property to a function to be called when that property is looked up.
- `__defineSetter__`: The `__defineSetter__` method binds an object's property to a function to be called when an attempt is made to set that property.
- `__lookupGetter__`: The `__lookupGetter__` method returns the function bound as a getter to the specified property.
- `__lookupSetter__`: The `__lookupSetter__` method returns the function bound as a setter to the specified property.

## 参见

- 属性索引