a = [1, ...[2,3], 4]; // [1, 2, 3, 4] // Concatenate arrays let x = ['a', 'b']; let y = ['c']; let z = ['d', 'e']; let xyz = [...x, ...y, ...z]; // ['a', 'b', 'c', 'd', 'e'] // Convert iterable objects to arrays let set = new Set([11, -1, 6]); let arr = [...set]; // [11, -1, 6] 32