30-seconds-of-code/snippets/head.md

title, tags, cover, firstSeen, lastUpdated

title	tags	cover	firstSeen	lastUpdated
Head of array	array	blog_images/clay-pot-horizon.jpg	2017-12-17T16:41:31+02:00	2020-10-19T22:49:51+03:00

Returns the head of an array.

• Check if arr is truthy and has a length property.
• Use arr[0] if possible to return the first element, otherwise return undefined.

const head = arr => (arr && arr.length ? arr[0] : undefined);

head([1, 2, 3]); // 1
head([]); // undefined
head(null); // undefined
head(undefined); // undefined