isUnique (original) (raw)
Examine if there are no duplicate values.
Similar: isUnique, isDisjoint, intersection.
function isUnique(x, fc, fm) // x: an array // fc: compare function (a, b) // fm: map function (v, i, x)
⏱️ Compare function ⇒ O(n²).
const xarray = require('extra-array');
var x = [1, 2, -1, -2]; xarray.isUnique(x); // → true
xarray.isUnique(x, (a, b) => Math.abs(a) - Math.abs(b)); // → false
xarray.isUnique(x, null, v => Math.abs(v)); // → false