这篇文章按照字母顺序列出了MDN里边所有的JavaScript属性。

Found 138 pages with the tag "Property":

## A

- `arguments`: The `function.arguments` property refers to an an array-like object corresponding to the arguments passed to a function. Use the simple variable `arguments` instead. This property is forbidden in strict model due to tail call optimization.
- `arguments[@@iterator]`: The initial value of the `@@iterator` property is the same function object as the initial value of the `Array.prototype.values` property.
- `arity`: The `arity` property used to return the number of arguments expected by the function, however, it no longer exists and has been replaced by the `Function.prototype.length` property.

## B

- `BYTES_PER_ELEMENT`: The `TypedArray.BYTES_PER_ELEMENT` property represents the size in bytes of each element in an typed array.
- `buffer`: The `buffer` accessor property represents the `ArrayBuffer` or `SharedArrayBuffer` referenced by the `DataView` at construction time.
- `buffer`: The `buffer` accessor property represents the `ArrayBuffer` referenced by a TypedArray at construction time.
- `buffer`: The `buffer` prototype property of the `Memory` object returns the buffer contained in the memory.
- `byteLength`: The `byteLength` accessor property represents the length of an `ArrayBuffer` in bytes.
- `byteLength`: The `byteLength` accessor property represents the length (in bytes) of this view from the start of its `ArrayBuffer` or `SharedArrayBuffer`.
- `byteLength`: The `byteLength` accessor property represents the length of an `SharedArrayBuffer` in bytes.
- `byteLength`: The `byteLength` accessor property represents the length (in bytes) of a typed array.
- `byteOffset`: The `byteOffset` accessor property represents the offset (in bytes) of this view from the start of its `ArrayBuffer` or `SharedArrayBuffer`.
- `byteOffset`: The `byteOffset` accessor property represents the offset (in bytes) of a typed array from the start of its `ArrayBuffer`.

## C

- `callee`: The `arguments.callee` property contains the currently executing function.
- `caller`: The obsolete `arguments.caller` property used to provide the function that invoked the currently executing function. This property has been removed and no longer works.
- `caller`: The `function.caller` property returns the function that invoked the specified function. This property is forbidden in strict model due to tail call optimization.
- `columnNumber`: The `columnNumber` property contains the column number in the line of the file that raised this error.
- `compare`: The `Intl.Collator.prototype.compare` property returns a function that compares two strings according to the sort order of this `Collator` object.
- `constructor`: The `constructor` property returns a reference to the `Object` constructor function that created the instance object. Note that the value of this property is a reference to the function itself, not a string containing the function's name. The value is only read-only for primitive values such as `1`, `true` and `"test"`.

## D

- `debuggerEnabled`: The `debug.debuggerEnabled` property determines whether debugging is enabled for the script context. Debugging may be enabled or disabled whether or not a debugger is attached.
- `delete operator`: The JavaScript `delete` operator removes a property from an object; if no more references to the same property are held, it is eventually released automatically.
- `description`: The read-only `description` property is a string returning the optional description of `Symbol` objects.
- `description`: The `Error.description` property returns or sets the descriptive string associated with a specific error.
- `displayName`: The `function.displayName` property returns the display name of the function.

## E

- `E`: The `Math.E` property represents the base of natural logarithms, e, approximately 2.718.
- `EPSILON`: The `Number.EPSILON` property represents the difference between 1 and the smallest floating point number greater than 1.
- `exports`: The `exports` readonly property of the `WebAssembly.Instance` object prototype returns an object containing as its members all the functions exported from the WebAssembly module instance, to allow them to be accessed and used by JavaScript.

## F

- `fileName`: The `fileName` property contains the path to the file that raised this error.
- `flags`: The `flags` property returns a string consisting of the flags of the current regular expression object.
- `format`: The `Intl.DateTimeFormat.prototype.format` property returns a getter function that formats a date according to the locale and formatting options of this `Intl.DateTimeFormat` object.
- `format`: The `Intl.NumberFormat.prototype.format` property returns a getter function that formats a number according to the locale and formatting options of this `NumberFormat` object.

## G

- `get ArrayBuffer[@@species]`: The `ArrayBuffer[@@species]` accessor property returns the `ArrayBuffer` constructor.
- `get Map[@@species]`: The `Map[@@species]` accessor property returns the `Map` constructor.
- `get RegExp[@@species]`: The `RegExp[@@species]` accessor property returns the `RegExp` constructor.
- `get Set[@@species]`: The `Set[@@species]` accessor property returns the `Set` constructor.
- `get TypedArray[@@species]`: The `TypedArray[@@species]` accessor property returns the constructor of a typed array.
- `global`: The `global` property indicates whether or not the "`g`" flag is used with the regular expression. `global` is a read-only property of an individual regular expression instance.

## H

- `hasInstance`: The `Symbol.hasInstance` well-known symbol is used to determine if a constructor object recognizes an object as its instance. The `instanceof` operator's behavior can be customized by this symbol.

## I

- `ignoreCase`: The `ignoreCase` property indicates whether or not the "`i`" flag is used with the regular expression. `ignoreCase` is a read-only property of an individual regular expression instance.
- `input ($_)`: The non-standard `input` property is a static property of regular expressions that contains the string against which a regular expression is matched. `RegExp.$_` is an alias for this property.
- `isConcatSpreadable`: The `Symbol.isConcatSpreadable` well-known symbol is used to configure if an object should be flattened to its array elements when using the `Array.prototype.concat()` method.
- `iterator`: The `Symbol.iterator` well-known symbol specifies the default iterator for an object. Used by `for...of`.

## J

## K

## L

- `LN10`: The `Math.LN10` property represents the natural logarithm of 10, approximately 2.302:
- `LN2`: The `Math.LN2` property represents the natural logarithm of 2, approximately 0.693:
- `LOG10E`: The `Math.LOG10E` property represents the base 10 logarithm of e, approximately 0.434:
- `LOG2E`: The `Math.LOG2E` property represents the base 2 logarithm of e, approximately 1.442:
- `lastIndex`: The `lastIndex` is a read/write integer property of regular expression instances that specifies the index at which to start the next match.
- `lastMatch ($&)`: The non-standard lastMatch property is a static and read-only property of regular expressions that contains the last matched characters. `RegExp.$&` is an alias for this property.
- `lastParen ($+)`: The non-standard lastParen property is a static and read-only property of regular expressions that contains the last parenthesized substring match, if any. `RegExp.$+` is an alias for this property.
- `leftContext ($`)`: The non-standard leftContext property is a static and read-only property of regular expressions that contains the substring preceding the most recent match. `RegExp.$`` is an alias for this property.
- `length`: The `arguments.length` property contains the number of arguments passed to the function.
- `length`: The `length` accessor property represents the length (in elements) of a typed array.
- `length`: The `length` property indicates the number of parameters expected by the function.
- `length`: The `length` property of an object which is an instance of type `Array` sets or returns the number of elements in that array. The value is an unsigned, 32-bit integer that is always numerically greater than the highest index in the array.
- `length`: The `length` property of a `String` object indicates the length of a string, in UTF-16 code units.
- `length`: The `length` prototype property of the `WebAssembly.Table` object returns the length of the table, i.e. the number of elements in the table.
- `lineNumber`: The `lineNumber` property contains the line number in the file that raised this error.

## M

- `MAX_SAFE_INTEGER`: The `Number.MAX_SAFE_INTEGER` constant represents the maximum safe integer in JavaScript (`253 - 1`).
- `MAX_VALUE`: The `Number.MAX_VALUE` property represents the maximum numeric value representable in JavaScript.
- `MIN_SAFE_INTEGER`: The `Number.MIN_SAFE_INTEGER` constant represents the minimum safe integer in JavaScript (`-(253 - 1)`).
- `MIN_VALUE`: The `Number.MIN_VALUE` property represents the smallest positive numeric value representable in JavaScript.
- `match`: The `Symbol.match` well-known symbol specifies the matching of a regular expression against a string. This function is called by the `String.prototype.match()` method.
- `message`: The `message` property is a human-readable description of the error.
- `msTraceAsyncCallbackCompleted`: Indicates that the callback stack associated with a previously specified asynchronous operation has completed.
- `multiline`: The `multiline` property indicates whether or not the "`m`" flag is used with the regular expression. `multiline` is a read-only property of an individual regular expression instance.

## N

- `NEGATIVE_INFINITY`: The `Number.NEGATIVE_INFINITY` property represents the negative Infinity value.
- `NaN`: The global `NaN` property is a value representing Not-A-Number.
- `NaN`: The `Number.NaN` property represents Not-A-Number. Equivalent of `NaN`.
- `name`: The `name` property represents a name for the type of error. The initial value is "Error".
- `name`: A `Function` object's read-only `name` property indicates the function's name as specified when it was created, or `"anonymous"` for functions created anonymously.
- `name`: The `TypedArray.name` property represents a string value of the typed array constructor name.
- `number`: The `Error.number` property returns or sets the numeric value associated with a specific error. The `Error` object's default property is number.

## O

## P

- `PI`: The `Math.PI` property represents the ratio of the circumference of a circle to its diameter, approximately 3.14159:
- `POSITIVE_INFINITY`: The `Number.POSITIVE_INFINITY` property represents the positive Infinity value.
- `parse: bad parsing`: `SyntaxError`
- `prototype`: The `Object.prototype` property represents the `Object` prototype object.
- `prototype`: The `ArrayBuffer.prototype` property represents the prototype for the `ArrayBuffer` object.
- `prototype`: The `Boolean.prototype` property represents the prototype for the `Boolean` constructor.
- `prototype`: The `DataView``.prototype` property represents the prototype for the `DataView` object.
- `prototype`: The `Date.prototype` property represents the prototype for the `Date` constructor.
- `prototype`: The `Error.prototype` property represents the prototype for the `Error` constructor.
- `prototype`: The `EvalError.prototype` property represents the prototype of the `EvalError` constructor.
- `prototype`: The `Function.prototype` property represents the `Function` prototype object.
- `prototype`: The `GeneratorFunction.prototype` property represents the `GeneratorFunction` prototype object.
- `prototype`: The `InternalError.prototype` property represents the prototype of the `InternalError` constructor.
- `prototype`: The `Intl.Collator.prototype` property represents the prototype object for the `Intl.Collator` constructor.
- `prototype`: The `Intl.DateTimeFormat.prototype` property represents the prototype object for the `Intl.DateTimeFormat` constructor.
- `prototype`: The `Intl.NumberFormat.prototype` property represents the prototype object for the `Intl.NumberFormat` constructor.
- `prototype`: The `Intl.PluralRules.prototype` property represents the prototype object for the `Intl.PluralRules` constructor.
- `prototype`: The `Intl.RelativeTimeFormat.prototype` property represents the prototype object for the `Intl.RelativeTimeFormat` constructor.
- `prototype`: The `Map``.prototype` property represents the prototype for the `Map` constructor.
- `prototype`: The `WebAssembly.Module``.prototype` property represents the prototype for the `WebAssembly.Module()` constructor.
- `prototype`: The `WebAssembly.Memory``.prototype` property represents the prototype for the `WebAssembly.Memory()` constructor.
- `prototype`: `Array` instances inherit from `Array.prototype`. As with all constructors, you can change the constructor's prototype object to make changes to all `Array` instances. For example, you can add new methods and properties to extend all `Array` objects. This is used for polyfilling, for example.
- `prototype`: The `Number.prototype` property represents the prototype for the `Number` constructor.
- `prototype`: The `AsyncFunction.prototype` property represents the `AsyncFunction` prototype object.
- `prototype`: The `Promise``.prototype` property represents the prototype for the `Promise` constructor.
- `prototype`: The `RangeError.prototype` property represents the prototype the `RangeError` constructor.
- `prototype`: The `ReferenceError.prototype` property represents the prototype for the `ReferenceError` constructor.
- `prototype`: The `RegExp.prototype` property represents the prototype object for the `RegExp` constructor.
- `prototype`: The `Set``.prototype` property represents the prototype for the `Set` constructor.
- `prototype`: The `SharedArrayBuffer.prototype` property represents the prototype for the `SharedArrayBuffer` object.
- `prototype`: The `String.prototype` property represents the `String` prototype object.
- `prototype`: The `Symbol``.prototype` property represents the prototype for the `Symbol` constructor.
- `prototype`: The `SyntaxError.prototype` property represents the prototype for the `SyntaxError` constructor.
- `prototype`: The `TypeError.prototype` property represents the prototype for the `TypeError` constructor.
- `prototype`: The `TypedArray``.prototype` property represents the prototype for `TypedArray` constructors.
- `prototype`: The `URIError.prototype` property represents the prototype for the `URIError` constructor.
- `prototype`: The `WeakMap``.prototype` property represents the prototype for the `WeakMap` constructor.
- `prototype`: The `WeakSet``.prototype` property represents the prototype for the `WeakSet` constructor.
- `prototype`: The `WebAssembly.Global``.prototype` property represents the prototype for the `WebAssembly.Global()` constructor.
- `prototype`: The `WebAssembly.Instance``.prototype` property represents the prototype for the `WebAssembly.Instance()` constructor.
- `prototype`: The `WebAssembly.Table``.prototype` property represents the prototype for the `WebAssembly.Table()` constructor.
- `prototype[@@toStringTag]`: The `Map[@@toStringTag]` property has an initial value of "Map".
- `prototype[@@unscopables]`: The `@@unscopable` symbol property contains property names that were not included in the ECMAScript standard prior to the ES2015 version. These properties are excluded from `with` statement bindings.

## Q

## R

- `replace`: The `Symbol.replace` well-known symbol specifies the method that replaces matched substrings of a string. This function is called by the `String.prototype.replace()` method.
- `rightContext ($')`: The non-standard rightContext property is a static and read-only property of regular expressions that contains the substring following the most recent match. `RegExp.$'` is an alias for this property.

## S

- `SQRT1_2`: The `Math.SQRT1_2` property represents the square root of 1/2 which is approximately 0.707:
- `SQRT2`: The `Math.SQRT2` property represents the square root of 2, approximately 1.414:
- `search`: The `Symbol.search` well-known symbol specifies the method that returns the index within a string that matches the regular expression. This function is called by the `String.prototype.search()` method.
- `setNonUserCodeExceptions`: If this property is set to `true` within a given scope, the debugger can then choose whether to take some specified action on exceptions thrown inside that scope: for instance, if the developer wishes to break on user-unhandled exceptions. Setting this property to `false` is the same as never having set the property.
- `size`: The `size` accessor property returns the number of elements in a `Set` object.
- `size`: The `size` accessor property returns the number of elements in a `Map` object.
- `source`: The `source` property returns a `String` containing the source text of the regexp object, and it doesn't contain the two forward slashes on both sides and any flags.
- `species`: The well-known symbol `Symbol.species` specifies a function-valued property that the constructor function uses to create derived objects.
- `split`: The `Symbol.split` well-known symbol specifies the method that splits a string at the indices that match a regular expression. This function is called by the `String.prototype.split()` method.
- `stack`: The non-standard `stack` property of `Error` objects offer a trace of which functions were called, in what order, from which line and file, and with what arguments. The stack string proceeds from the most recent calls to earlier ones, leading back to the original global scope call.
- `stackTraceLimit`: The `Error.stackTraceLimit` property gets or sets the stack trace limit, which is equivalent to the number of error frames to display. The default limit is 10.
- `sticky`: The `sticky` property reflects whether or not the search is sticky (searches in strings only from the index indicated by the `lastIndex` property of this regular expression). `sticky` is a read-only property of an individual regular expression object.

## T

- `toPrimitive`: The `Symbol.toPrimitive` is a symbol that specifies a function valued property that is called to convert an object to a corresponding primitive value.
- `toStringTag`: The `Symbol.toStringTag` well-known symbol is a string valued property that is used in the creation of the default string description of an object. It is accessed internally by the `Object.prototype.toString()` method.

## U

- `unicode`: The `unicode` property indicates whether or not the "`u`" flag is used with a regular expression. `unicode` is a read-only property of an individual regular expression instance.
- `unscopables`: The `Symbol.unscopables` well-known symbol is used to specify an object value of whose own and inherited property names are excluded from the `with` environment bindings of the associated object.

## V

## W

## X

## Y

## Z

## _

- `__count__`: The `__count__` property used to store the count of enumerable properties on the object, but it has been removed.
- `__noSuchMethod__`: The `__noSuchMethod__` property used to reference a function to be executed when a non-existent method is called on an object, but this function is no longer available.
- `__parent__`: The `__parent__` property used to point to an object's context, but it has been removed.
- `__proto__`: The `__proto__` property of `Object.prototype` is an accessor property (a getter function and a setter function) that exposes the internal `[[Prototype]]` (either an object or `null`) of the object through which it is accessed.

## $

- `$1-$9`: The non-standard $1, $2, $3, $4, $5, $6, $7, $8, $9 properties are static and read-only properties of regular expressions that contain parenthesized substring matches.

## See also

- Methods index