27 lines
642 B
Markdown
27 lines
642 B
Markdown
---
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title: juxt
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tags: array,function,advanced
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---
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Takes several functions as argument and returns a function that is the juxtaposition of those functions.
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Use `Array.prototype.map()` to return a `fn` that can take a variable number of `args`.
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When `fn` is called, return an array containing the result of applying each `fn` to the `args`.
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```js
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const juxt = (...fns) => (...args) => [...fns].map(fn => [...args].map(fn));
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```
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```js
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juxt(
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x => x + 1,
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x => x - 1,
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x => x * 10
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)(1, 2, 3) // [[2,3,4],[0,1,2],[10,20,30]]
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juxt(
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s => s.length,
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s => s.split(" ").join("-")
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)("30 seconds of code") // [[18],['30-seconds-of-code']]
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```
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