Removes duplicate values.
Alternatives: compare, map.
This is part of package extra-array.
This is browserified, minified version of @extra-array/unique-on.
It is exported as global variable array_uniqueOn.
CDN: unpkg, jsDelivr.
array.uniqueOn(x, [fn], [ths]);
// x: an array
// fn: map function (v, i, x)
// ths: this argument
const array = require('extra-array');
var x = [1, 2, 3, 4, 2, 3];
array.uniqueOn(x);
// [1, 2, 3, 4]
var x = [1, 2, 3, 4, -2, -3];
array.uniqueOn(x, v => Math.abs(v));
// [1, 2, 3, 4]