Array.isArray() 用于确定传递的值是否是一个 `Array`。

    Array.isArray([1, 2, 3]);
    // true
    Array.isArray({foo: 123});
    // false
    Array.isArray("foobar");
    // false
    Array.isArray(undefined);
    // false

## 语法

    Array.isArray(obj)

### 参数

`obj`
  需要检测的值。

### 返回值

如果对象是 `Array`，则为true; 否则为false。

## 描述

如果对象是 `Array` ，则返回true，否则为false。

有关更多详细信息，请参阅文章严格判定JavaScript对象是否为数组。

## 示例

    // 下面的函数调用都返回 true
    Array.isArray([]);
    Array.isArray([1]);
    Array.isArray(new Array());
    // 鲜为人知的事实：其实 Array.prototype 也是一个数组。
    Array.isArray(Array.prototype);

    // 下面的函数调用都返回 false
    Array.isArray();
    Array.isArray({});
    Array.isArray(null);
    Array.isArray(undefined);
    Array.isArray(17);
    Array.isArray('Array');
    Array.isArray(true);
    Array.isArray(false);
    Array.isArray({ __proto__: Array.prototype });

### `instanceof` 和 `isArray`

当检测Array实例时, `Array.isArray` 优于 `instanceof,因为Array.isArray能检测iframes`.

    var iframe = document.createElement('iframe');
    document.body.appendChild(iframe);
    xArray = window.frames[window.frames.length-1].Array;
    var arr = new xArray(1,2,3); // [1,2,3]

    // Correctly checking for Array
    Array.isArray(arr);  // true
    // Considered harmful, because doesn't work though iframes
    arr instanceof Array; // false

## Polyfill

假如不存在 Array.isArray()，则在其他代码之前运行下面的代码将创建该方法。

    if (!Array.isArray) {
      Array.isArray = function(arg) {
        return Object.prototype.toString.call(arg) === '[object Array]';
      };
    }

## 规范

Specification | Status | Comment
--- | --- | ---
ECMAScript 5.1 (ECMA-262) Array.isArray | Standard | Initial definition. Implemented in JavaScript 1.8.5.
ECMAScript 2015 (6th Edition, ECMA-262) Array.isArray | Standard |
ECMAScript Latest Draft (ECMA-262) Array.isArray | Draft |

## 浏览器兼容性

The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

Update compatibility data on GitHub

| Desktop | Mobile | Server
| Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | Android webview | Chrome for Android | Edge Mobile | Firefox for Android | Opera for Android | Safari on iOS | Samsung Internet | Node.js
`isArray` | Chrome Full support 5 | Edge Full support 12 | Firefox Full support 4 | IE Full support 9 | Opera Full support 10.5 | Safari Full support 5 | WebView Android Full support Yes | Chrome Android Full support Yes | Edge Mobile Full support Yes | Firefox Android Full support 4 | Opera Android Full support Yes | Safari iOS Full support Yes | Samsung Internet Android Full support Yes | nodejs Full support Yes

### Legend

Full support
  Full support

## 相关链接

- `Array`