30-seconds-of-code/snippets/js/s/toggle-array-element.md

title, type, language, tags, author, cover, dateModified

title	type	language	tags	author	cover	dateModified
Toggle element in array	snippet	javascript	array	chalarangelo	digital-nomad-7	2022-04-15T05:00:00-04:00

Removes an element from an array if it's included in the array, or pushes it to the array if it isn't.

• Use Array.prototype.includes() to check if the given element is in the array.
• Use Array.prototype.filter() to remove the element if it's in the array.
• Use the spread operator (...) to push the element if it's not in the array.

const toggleElement = (arr, val) =>
  arr.includes(val) ? arr.filter(el => el !== val) : [...arr, val];

toggleElement([1, 2, 3], 2); // [1, 3]
toggleElement([1, 2, 3], 4); // [1, 2, 3, 4]