How to Concatenate Two Strings with Comma in Javascript

In this tutorial, you will learn how to concatenate two strings with comma in javascript. A meaningless phrase or string might gain some depth if one or more strings are added to it. In an English sentence, a comma is put after the first clause or phrase. For a newbie developer, it can be a bit tricky to concatenate two strings with comma.

There are numerous ways to concatenate two strings with comma. But for the sake of simplicity, we will make use of addition operator (+) which helps in concatenating two or more strings.

In the following example, we have two global variables that are holding a string value. Upon click of a button, we will concatenate the two strings with comma and display the result on the screen.  Please have a look over the code example and the steps given below.


  • We have 3 elements in the HTML file (div, button, and h1). The div element is just a wrapper for the rest of the elements.
  • The innerText for the button element is “Add” and for the h1 element, it is “Result”.
  • We have done some basic styling using CSS and added the link to our style.css stylesheet inside the head element.
  • We have also included our javascript file script.js with a script tag at the bottom.
<!DOCTYPE html>
<html lang="en">

  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <link rel="stylesheet" href="style.css">


  <div class="container">    

  <script src="script.js"></script>

.container {        
    text-align: center;

button {
  margin-top: 10px;
  padding: 10px 20px;


  • We have selected the button element and h1 element using the document.querySelector() method and stored them in btnAdd and output variables respectively.
  • We have two global variables firstName and lastName. They both hold a string as a value.
  • We have attached a click event listener to the button element.
  • In the event handler function, we are concatenating firstName and lastName variables using addition operator (+) .
  • We are storing the final string in the result variable.
  • We are displaying the result in the h1 element using the innerText property.
let btnAdd = document.querySelector("button");
let output = document.querySelector("h1");

let firstName = `Dean`;
let lastName = `Mean`;
btnAdd.addEventListener("click", () => {  
  let result = lastName + ',' + firstName;
  output.innerText = result;