25 lines
863 B
Markdown
25 lines
863 B
Markdown
---
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title: zip
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tags: array,intermediate
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---
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Creates an array of elements, grouped based on their position in the original arrays.
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- Use `Math.max()`, `Function.prototype.apply()` to get the longest array in the arguments.
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- Create an array with that length as return value and use `Array.from()` with a mapping function to create an array of grouped elements.
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- If lengths of the argument arrays vary, `undefined` is used where no value could be found.
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```js
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const zip = (...arrays) => {
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const maxLength = Math.max(...arrays.map(x => x.length));
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return Array.from({ length: maxLength }).map((_, i) => {
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return Array.from({ length: arrays.length }, (_, k) => arrays[k][i]);
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});
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};
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```
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```js
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zip(['a', 'b'], [1, 2], [true, false]); // [['a', 1, true], ['b', 2, false]]
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zip(['a'], [1, 2], [true, false]); // [['a', 1, true], [undefined, 2, false]]
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```
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