Using Array concat() method to coding in Javascript/JS

This JavaScript tutorial explains how to use the Array method called concat() with syntax and examples.


In JavaScript, concat() is an Array approach that is used to concatenate two or greater arrays into a new array. Because the concat() method is a technique of the Array object, it need to be invoked via a unique occasion of the Array class.


In JavaScript, the syntax for the concat() approach is:

array.concat(value1, value2, ... value_n);

Parameters or Arguments

value1, value2, … value_n Optional. The values or arrays that will be concatenated with array.


The concat() method returns a new array with the factors of the calling array observed by means of the concatenation of every of the parameters, in their respective order.


The concat() method does no longer alternate the original array or any of the values supplied as parameters.


Let’s take a look at an example of how to use the concat() approach in JavaScript.

For example:

var totn_array1 = ['Tech','On'];
var totn_array2 = ['The','Net'];


In this example, we have declared two array objects known as totn_array1 and totn_array2, each with 2 elements. We have then invoked the concat() method of the totn_array1 variable to return a new array that concatenates the two arrays together.

We have written the output of the concat() approach to the web browser console log, for demonstration purposes, to show what the concat() method returns.

The following will be output to the net browser console log:

["Tech", "On", "The", "Net"]

In this example, the concat() approach will return a new array of four factors consisting of the strings “Tech”, “On”, “The”, and “Net”.

Concatenating Values to the Array

The concat() approach can additionally concatenate values to an array.

For example:

var totn_array = ['Tech','On','The','Net'];


The following will be output to the net browser console log:

["Tech", "On", "The", "Net", 1, 2, "a", "b"]

In this example, we have used the concat() approach to create a new array that concatenates the array [‘Tech’,’On’,’The’,’Net’] with the values 1, 2, “a” and “b”. This creates a new array with eight elements. Notice that you can concatenation specific sorts of factors – some of the elements in the new array are string values while others are numeric values.