NodeList.prototype.forEach()

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句法
范例
Polyfill
规范
浏览器兼容性
另请参阅
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forEach() 方法在 NodeList interface calls the callback given in parameter once for each value pair in the list, in insertion order.

句法

someNodeList.forEach(callback[, thisArg]);

参数

callback

currentValue: The current element being processed in someNodeList .
currentIndex 可选: The index of the currentValue being processed in someNodeList .
listObj 可选: someNodeList that forEach() is being applied to.

thisArg 可选: Value to use as this when executing callback .

返回值

undefined .

范例

let node = document.createElement("div");
let kid1 = document.createElement("p");
let kid2 = document.createTextNode("hey");
let kid3 = document.createElement("span");
node.appendChild(kid1);
node.appendChild(kid2);
node.appendChild(kid3);
let list = node.childNodes;
list.forEach(
  function(currentValue, currentIndex, listObj) {
    console.log(currentValue + ', ' + currentIndex + ', ' + this);
  },
  'myThisArg'
);

The above code results in the following:

[object HTMLParagraphElement], 0, myThisArg
[object Text], 1, myThisArg
[object HTMLSpanElement], 2, myThisArg

Polyfill

This polyfill adds compatibility to all Browsers supporting ES5 :

if (window.NodeList && !NodeList.prototype.forEach) {
    NodeList.prototype.forEach = function (callback, thisArg) {
        thisArg = thisArg || window;
        for (var i = 0; i < this.length; i++) {
            callback.call(thisArg, this[i], i, this);
        }
    };
}

if (window.NodeList && !NodeList.prototype.forEach) {
   NodeList.prototype.forEach = Array.prototype.forEach;
}

The above behavior is how many browsers actually implement NodeList.prototype.forEach() (Chrome, for example).

规范

规范	状态	注释
Web IDL The definition of 'forEach' in that specification.	候选推荐	定义 `forEach` on `iterable` declarations

浏览器兼容性

The compatibility table on 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. 更新 GitHub 上的兼容性数据

	桌面						移动
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`forEach`	Chrome 51	Edge 16	Firefox 50	IE No	Opera 38	Safari 10	WebView Android 51	Chrome Android 51	Firefox Android 50	Opera Android 41	Safari iOS 10	Samsung Internet Android 5.0

图例

完整支持
不支持

另请参阅

元数据

最后修改： Mar 18, 2020

DOM (文档对象模型)
NodeList
特性
1. length
方法
1. entries()
2. forEach()
3. item()
4. keys()
5. values()
DOM 相关页面

在此页

句法

参数

返回值

范例

Polyfill

规范

浏览器兼容性

图例

另请参阅

相关话题