.concat is not a function javascript code example

Example: 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);