499 B
499 B
title, tags, cover, firstSeen, lastUpdated
| title | tags | cover | firstSeen | lastUpdated |
|---|---|---|---|---|
| Head of array | array | clay-pot-horizon | 2017-12-17T16:41:31+02:00 | 2020-10-19T22:49:51+03:00 |
Returns the head of an array.
- Check if
arris truthy and has alengthproperty. - Use
arr[0]if possible to return the first element, otherwise returnundefined.
const head = arr => (arr && arr.length ? arr[0] : undefined);
head([1, 2, 3]); // 1
head([]); // undefined
head(null); // undefined
head(undefined); // undefined