20 lines
395 B
Markdown
20 lines
395 B
Markdown
---
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title: head
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tags: array,beginner
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---
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Returns the head of a list.
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- Check if `arr` is truthy and has a `length` property, use `arr[0]` if possible to return the first element, otherwise return `undefined`.
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```js
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const head = arr => (arr && arr.length ? arr[0] : undefined);
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```
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```js
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head([1, 2, 3]); // 1
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head([]); // undefined
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head(null); // undefined
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head(undefined); // undefined
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```
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