add new number in a list JS code example

Example 1: javascript append element to array

var colors= ["red","blue"];
	colors.push("yellow");

Example 2: javascript adding an array to an array

let chocholates = ['Mars', 'BarOne', 'Tex'];
let chips = ['Doritos', 'Lays', 'Simba'];
let sweets = ['JellyTots'];

let snacks = [];
snacks.concat(chocholates);
// snacks will now be ['Mars', 'BarOne', 'Tex']
// Similarly if we left the snacks array empty and used the following
snacks.concat(chocolates, chips, sweets);
//This would return the snacks array with all other arrays combined together
// ['Mars', 'BarOne', 'Tex', 'Doritos', 'Lays', 'Simba', 'JellyTots']

Example 3: javascript append array to end of array

const new_array = old_array.concat([value1[, value2[, ...[, valueN]]]])