push to existing object javascript concatenate code example

Example 1: merge array in js

//for ES5
var array1 = ["Rahul", "Sachin"];
var array2 = ["Sehwag", "Kohli"];

var output = array1.concat(array2);
console.log(output);

//for ES6, we use spread operators to concat arrays

var array1 = ["Dravid", "Tendulkar"];
var array2 = ["Virendra", "Virat"];

var output = [...array1, ...array2];
console.log(output);

Example 2: concat js mdn

const array1 = ['a', 'b', 'c'];
const array2 = ['d', 'e', 'f'];
const array3 = array1.concat(array2);

console.log(array3);
// expected output: Array ["a", "b", "c", "d", "e", "f"]