67 lines
1.7 KiB
Markdown
67 lines
1.7 KiB
Markdown
---
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title: How can I clone an array in JavaScript?
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shortTitle: Clone an array
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type: question
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tags: [javascript,array]
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author: chalarangelo
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cover: colorful-plastic
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excerpt: Pick up a few new tricks which you can use to clone arrays in JavaScript.
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dateModified: 2021-06-12T19:30:41+03:00
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---
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JavaScript provides quite a few ways to clone an array, most of which are pretty similar in terms of performance and results. Here's a quick rundown of some of the available options.
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#### The spread operator
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ES6 introduced the spread operator (`...`), which provides probably the easiest and most common way to create a shallow clone of an array.
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```js
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let x = [1, 2, 3, 4];
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let y = [...x];
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```
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#### Array.from()
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`Array.from()` has a very powerful API that can be used for many different things, including creating a copy of an array.
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```js
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let x = [1, 2, 3, 4];
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let y = Array.from(x);
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```
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#### Array.prototype.slice()
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Similarly to the spread operator, `Array.prototype.slice()` can be used to create a shallow copy of an array.
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```js
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let x = [1, 2, 3, 4];
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let y = x.slice();
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```
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#### Array.prototype.map()
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Looking into one of the more unorthodox options, `Array.prototype.map()` can be used to map each element of an array to itself to create a new array.
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```js
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let x = [1, 2, 3, 4];
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let y = x.map(i => i);
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```
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#### Array.prototype.filter()
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Similarly, `Array.prototype.filter()` can be used to return `true` for each and every element, resulting in a new array with all of the original array's elements.
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```js
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let x = [1, 2, 3, 4];
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let y = x.filter(() => true);
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```
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#### Object.assign()
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Finally, `Object.assign()` can be used in the exact same way as it's used to create a clone of an object, but for an array instead.
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```js
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let x = [1, 2, 3, 4];
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let y = Object.assign([], x);
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```
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