union

Gives values present in any array. 🏃 📼 📦 🌔 📒

Alternatives: [union], [union$].
Similar: [union], [intersection], [difference], [unique], [isUnique], [isDisjoint].

array.union(x, y, [fc], [fm]);
// x:  an array
// y:  another array
// fc: compare function (a, b)
// fm: map function (v, i, x)

⏱️ Compare function => O(n²).

const array = require('extra-array');

var x = [1, 2, 3, 4];
var y = [2, 3, 5];
array.union(x, y);
// [ 1, 2, 3, 4, 5 ]

var y = [-2, -3, -5];
array.union(x, y, (a, b) => Math.abs(a) - Math.abs(b));
// [ 1, 2, 3, 4, -5 ]

array.union(x, y, null, v => Math.abs(v));
// [ 1, 2, 3, 4, -5 ]

references

• Data.Set.union: Haskell
• _.union: lodash
• Set.union: Python