Array Extend without custom method?

Question

Is it possible to use Array.push to add multiple values from a list? For example, currently what I'm having to do is:

Array.prototype.extend = function(arr) {
    for (let elem of arr) {
        this.push(elem);
    }
}
let x = [1,2,3];
let y = [4,5,6];
let z = [7,8,9];
x.push(y);
x.extend(z)
console.log(x);

Or, is there some way to pass the array as a single argument to the push method, or perhaps there's another Array method entirely that does this instead?

Answer 1

you can spread the array element like this

const x = [1,2,3];
const y = [4,5,6];
const z = [7,8,9];
x.push(...y);
x.push(...z)
console.log(x);

Answer 2

You can push multiple arguments to Array.prototype.push and they'll all be pushed to our result array, so we can "convert" our array into multiple arguments using the ES6 spread syntax.

let x = [1,2,3];
let y = [4,5,6];
x.push(...y);
console.log(x);