CODE EXAMPLE FOR JAVASCRIPT

javascript combine array of arrays

/* Flatten (merge) an array of arrays with reduce & concat */
let myArrays = [[1, 2, 3], [4, 5], [6]];
myArrays.reduce((initial, current) => initial.concat(current), []);
// → [1, 2, 3, 4, 5, 6]


/* Join multiple arrays together. */
let warm = ["red", "orange"];
let cool = ["blue", "purple"];
let neutral = ["brown", "gray"];
let colors = warm.concat(cool).concat(neutral);
// → ["red", "orange", "blue", "purple", "brown", "gray"]