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30-seconds-of-code/snippets/array-zip.md
2017-12-14 23:56:51 +01:00

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### Array zip
Use `Math.max.apply` to get the longest array in the arguments.
Creates an array with that length as return value and use `Array.from` with a map-function to create an array of grouped elements.
If lengths of the argument-arrays vary, `undefined` is used where no value could be found.
```js
const zip = (...arrays) => {
const maxLength = Math.max.apply(null, arrays.map(a => a.length));
return Array.from({length: maxLength}).map((_, i) => {
return Array.from({length: arrays.length}, (_, k) => arrays[k][i])
})
}
//zip(['a', 'b'], [1, 2], [true, false]); -> [['a', 1, true], ['b', 2, false]]
//zip(['a'], [1, 2], [true, false]); -> [['a', 1, true], [undefined, 2, false]]
```