14 lines
321 B
Markdown
14 lines
321 B
Markdown
### intersection
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Returns a list of elements that exist in both arrays.
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Create a `Set` from `b`, then use `Array.filter()` on `a` to only keep values contained in `b`.
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```js
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const intersection = (a, b) => { const s = new Set(b); return a.filter(x => s.has(x)); };
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```
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```js
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intersection([1,2,3], [4,3,2]) // [2,3]
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```
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