43 lines
1.0 KiB
Markdown
43 lines
1.0 KiB
Markdown
---
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title: Spread Operator
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---
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## Spread Operator
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The spread operator (`...`), allows to get the elements of a collection.
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One of the most commom uses is for `Node` Objects, when using query selectors in the browser, in order to make them iterable Array Objects:
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```javascript
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const paragraphs = document.querySelectorAll('p.paragraph');
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const arr = [...paragraphs];
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```
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Another use of the spread operator is for Array concatenation:
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```javascript
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const arr_1 = [1, 2, 3, 4]
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const arr_2 = [5, 6, 7, 8]
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const arr_final = [...arr_1, ...arr_2]
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// arr_final = [1, 2, 3, 4, 5, 6, 7, 8]
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```
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The spread operator can also copy enumerable properties from one or more objects onto a new object:
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```javascript
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const obj1 = {
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a: 1,
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b: 2,
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c: 3
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};
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const obj2 = {
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d: 4,
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e: 5,
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f: 6
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};
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const newObj = {...obj1, ...obj2);
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// newObj = { a: 1, b: 2, c: 3, d: 4, e: 5, f: 6 }
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```
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### More Information:
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- [MDN - Spread Syntax](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Spread_syntax)
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