29 lines
860 B
Markdown
29 lines
860 B
Markdown
---
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title: Ungroup array elements
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type: snippet
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language: javascript
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tags: [array]
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cover: glass-blowing
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dateModified: 2020-10-22T20:24:44+03:00
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---
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Creates an array of arrays, ungrouping the elements in an array produced by [zip](/js/s/zip).
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- Use `Math.max()`, `Function.prototype.apply()` to get the longest subarray in the array, `Array.prototype.map()` to make each element an array.
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- Use `Array.prototype.reduce()` and `Array.prototype.forEach()` to map grouped values to individual arrays.
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```js
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const unzip = arr =>
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arr.reduce(
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(acc, val) => (val.forEach((v, i) => acc[i].push(v)), acc),
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Array.from({
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length: Math.max(...arr.map(x => x.length))
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}).map(x => [])
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);
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```
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```js
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unzip([['a', 1, true], ['b', 2, false]]); // [['a', 'b'], [1, 2], [true, false]]
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unzip([['a', 1, true], ['b', 2]]); // [['a', 'b'], [1, 2], [true]]
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```
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