JS: Array.from

By Xah Lee. Date: . Last updated: .

New in ES2015.

Converts a iterable object items to array.

〔►see JS: Iterable

If thisArg is given, it will be used as this value of f. If it is not given, undefined is used.

〔►see JS: “this” Binding

const ss = new Set ([3,4,5]); // a set object
const ar = Array.from(ss);    // convert set to array object
console.log(ar) // [ 3, 4, 5 ]

Array.from ( items, f ) example:

// a set object
const ss = new Set ([3,4,5]);

// convert to array, but add one to each
const ar = Array.from(ss, x => x +1);

console.log(ar); // [ 4, 5, 6 ]

Reference

ECMAScript® 2016 Language Specification#sec-array.from

Array Topic

  1. JS: Array Basics
  2. JS: Understand JS Array
  3. JS: Create Array
  4. JS: Sparse Array
  5. JS: Array-Like Object
  6. JS: Array How-To

  1. JS: Array Object
  2. JS: Array.prototype
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