javascript, how to push to an array inside another array code example

Example 1: javscript append item from array

let foo = ['oop','plop','copo'];
	foo.push("plop");

Example 2: how to push an element into an array in javascript

// initialize array
var arr = [
  "Hi",
  "Hello",
  "Bonjour"
];

// append new value to the array
arr.push("Hola");

console.log(arr);