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30-seconds-of-code/snippets/head.md
Angelos Chalaris 8a6b73bd0c Update covers
2023-02-16 22:24:28 +02:00

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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 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