how to push element in array in javascript in node js code example

Example 1: js array push

const arr = ["foo", "bar"];
arr.push('baz'); // 3
arr; // ["foo", "bar", "baz"]

Example 2: js add array items to array

var arrayA = [1, 2];
var arrayB = [3, 4];
var newArray = arrayA.concat(arrayB);