在此页

• 句法
• 描述
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

push() method adds one or more elements to the end of an array and returns the new length of the array.

The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request.

句法

arr.push([element1[, ...[, elementN]]])
					

参数

element N

The element(s) to add to the end of the array.

返回值

The new length property of the object upon which the method was called.

描述

push method appends values to an array.

push is intentionally generic. This method can be used with call() or apply() on objects resembling arrays. The push method relies on a length property to determine where to start inserting the given values. If the length property cannot be converted into a number, the index used is 0. This includes the possibility of length being nonexistent, in which case length will also be created.

Although strings are native, Array-like objects, they are not suitable in applications of this method, as strings are immutable.  Similarly for the native, Array-like object arguments .

范例

Adding elements to an array

The following code creates the sports array containing two elements, then appends two elements to it. The total variable contains the new length of the array.

let sports = ['soccer', 'baseball']
let total = sports.push('football', 'swimming')
console.log(sports)  // ['soccer', 'baseball', 'football', 'swimming']
console.log(total)   // 4
					

Merging two arrays

此范例使用 apply() to push all elements from a second array.

Do not use this method if the second array ( moreVegs in the example) is very large because the maximum number of parameters that one function can take is limited in practice. See apply() 了解更多细节。

let vegetables = ['parsnip', 'potato']
let moreVegs = ['celery', 'beetroot']
// Merge the second array into the first one
// Equivalent to vegetables.push('celery', 'beetroot')
Array.prototype.push.apply(vegetables, moreVegs)
console.log(vegetables)  // ['parsnip', 'potato', 'celery', 'beetroot']
					

Using an object in an array-like fashion

As mentioned above, push is intentionally generic, and we can use that to our advantage. Array.prototype.push can work on an object just fine, as this example shows.

Note that we don't create an array to store a collection of objects. Instead, we store the collection on the object itself and use call on Array.prototype.push to trick the method into thinking we are dealing with an array—and it just works, thanks to the way JavaScript allows us to establish the execution context in any way we want.

let obj = {
    length: 0,
    addElem: function addElem(elem) {
        // obj.length is automatically incremented
        // every time an element is added.
        [].push.call(this, elem)
    }
}
// Let's add some empty objects just to illustrate.
obj.addElem({})
obj.addElem({})
console.log(obj.length)
// → 2
					

Note that although obj is not an array, the method push successfully incremented obj 's length property just like if we were dealing with an actual array.

规范

规范
ECMAScript (ECMA-262) The definition of 'Array.prototype.push' in that specification.

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. 更新 GitHub 上的兼容性数据

	Desktop						Mobile						Server
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet	Node.js
push	Chrome 1	Edge 12	Firefox 1	IE 5.5	Opera 4	Safari 1	WebView Android 1	Chrome Android 18	Firefox Android 4	Opera Android 10.1	Safari iOS 1	Samsung Internet Android 1.0	nodejs 0.1.100

图例

完整支持

完整支持

另请参阅

• Array.prototype.pop()
• Array.prototype.shift()
• Array.prototype.unshift()
• Array.prototype.concat()

元数据

• 最后修改： Aug 5, 2020

相关话题

1. 标准内置对象
2. Array
3. 特性
   1. Array.prototype.length
   2. Array.prototype[@@unscopables]
4. 方法
   1. Array.from()
   2. Array.isArray()
   3. Array.of()
   4. Array.prototype.concat()
   5. Array.prototype.copyWithin()
   6. Array.prototype.entries()
   7. Array.prototype.every()
   8. Array.prototype.fill()
   9. Array.prototype.filter()
   10. Array.prototype.find()
   11. Array.prototype.findIndex()
   12. Array.prototype.flat()
   13. Array.prototype.flatMap()
   14. Array.prototype.forEach()
   15. Array.prototype.includes()
   16. Array.prototype.indexOf()
   17. Array.prototype.join()
   18. Array.prototype.keys()
   19. Array.prototype.lastIndexOf()
   20. Array.prototype.map()
   21. Array.prototype.pop()
   22. Array.prototype.push()
   23. Array.prototype.reduce()
   24. Array.prototype.reduceRight()
   25. Array.prototype.reverse()
   26. Array.prototype.shift()
   27. Array.prototype.slice()
   28. Array.prototype.some()
   29. Array.prototype.sort()
   30. Array.prototype.splice()
   31. Array.prototype.toLocaleString()
   32. Array.prototype.toSource()
   33. Array.prototype.toString()
   34. Array.prototype.unshift()
   35. Array.prototype.values()
   36. Array.prototype[@@iterator]()
   37. get Array[@@species]
5. 继承：
6. Function
7. 特性
   1. Function.arguments
   2. Function.caller
   3. Function.displayName
   4. Function.length
   5. Function.name
8. 方法
   1. Function.prototype.apply()
   2. Function.prototype.bind()
   3. Function.prototype.call()
   4. Function.prototype.toSource()
   5. Function.prototype.toString()
9. Object
10. 特性
    1. Object.prototype.__proto__
    2. Object.prototype.constructor
11. 方法
    1. Object.prototype.__defineGetter__()
    2. Object.prototype.__defineSetter__()
    3. Object.prototype.__lookupGetter__()
    4. Object.prototype.__lookupSetter__()
    5. Object.prototype.hasOwnProperty()
    6. Object.prototype.isPrototypeOf()
    7. Object.prototype.propertyIsEnumerable()
    8. Object.prototype.toLocaleString()
    9. Object.prototype.toSource()
    10. Object.prototype.toString()
    11. Object.prototype.valueOf()
    12. Object.setPrototypeOf()