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

title, tags, expertise, author, cover, firstSeen

title	tags	expertise	author	cover	firstSeen
Toggle element in array	array	beginner	chalarangelo	blog_images/digital-nomad-7.jpg	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]