join 2 array in javascript

const array1 = ["Vijendra","Singh"];
const array2 = ["Singh", "Shakya"];
const array3 = [...array1, ...array2];

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

console.log(array1.concat(array2));

[1,2,3].concat([4,5,6])
// [1,2,3,4,5,6]

// using push and apply to return the same array
const arr1 = ['a', 'b'];
const arr2 = ['c', 'd'];
arr1.push.apply(arr1, arr2);
console.log(arr1) // ['a', 'b', 'c', 'd']