Array.of() - JavaScript 编辑

The Array.of() method creates a new Array instance from a variable number of arguments, regardless of number or type of the arguments.

The difference between Array.of() and the Array constructor is in the handling of integer arguments: Array.of(7) creates an array with a single element, 7, whereas Array(7) creates an empty array with a length property of 7 (Note: this implies an array of 7 empty slots, not slots with actual undefined values).

Array.of(7); // [7]
Array(7); // array of 7 empty slots

Array.of(1, 2, 3); // [1, 2, 3]
Array(1, 2, 3);    // [1, 2, 3]

Syntax

Array.of(element0[, element1[, ...[, elementN]]])

Parameters

elementN

Elements used to create the array.

Return value

A new Array instance.

Description

This function is part of the ECMAScript 2015 standard.

For more information, see:

• Array.of()
• Array.from() proposal
• Array.of() polyfill

Polyfill

Running the following code before any other code will create Array.of() if it's not natively available.

if (!Array.of) {
  Array.of = function() {
    return Array.prototype.slice.call(arguments);
    // Or
    let vals = [];
    for(let prop in arguments){
        vals.push(arguments[prop]);
    }
    return vals;
  }
}

Examples

Using Array.of

Array.of(1);         // [1]
Array.of(1, 2, 3);   // [1, 2, 3]
Array.of(undefined); // [undefined]

Specifications

Browser compatibility

BCD tables only load in the browser

See also

• Array
• Array.from()
• TypedArray.of()