Array | filterNonUnique

Fri Apr 08 2022 13:07:53 GMT+0000 (Coordinated Universal Time)

Saved by @massa

const filterNonUnique = arr => arr.filter(i => arr.indexOf(i) === arr.lastIndexOf(i));

filterNonUnique([1, 2, 2, 3, 4, 4, 5]); // [1, 3, 5]

Filters out the non-unique values in an array. Use Array.prototype.filter() for an array containing only the unique values.