how to concat list in one js code example

Example 1: js merge 2 lists

var array1 = ["Vijendra", "Singh"];
var array2 = ["Singh", "Shakya"];

console.log(array1.concat(array2));
// output: ["Vijendra", "Singh", "Singh", "Shakya"]

Example 2: array concat in javascript

const letters = ['a', 'b', 'c'];
const numbers = [1, 2, 3];

const newArray = letters.concat(numbers);
// newArrat is ['a', 'b', 'c', 1, 2, 3]