How to Concatenate Two Integers in Javascript

In this tutorial, you will learn how to concatenate two integers in javascript. A string is made up of text, which can be made up of different combinations of letters, numbers, punctuation, special characters, etc. The digits in a number range from 0 to 9. For a newbie developer, it can be a bit tricky to concatenate two integers.

There are numerous ways to concatenate two integers. But for the sake of simplicity, we will make use of template string which helps in creating a dynamic string by using variables in it.

In the following example, we have two global variables that are holding numbers. Upon click of a button, we will concatenate two integers 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 (divbutton, 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 num1 and num2. They both hold a number as a value.
  • We have attached a click event listener to the button element.
  • In the event handler function, we are creating a string dynamically where we we are using global variables num1 and num2 .
  • 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 num1 = 2;
let num2 = 3;
btnAdd.addEventListener("click", () => {  
  let result = `${num1}${num2}`;
  output.innerText = result;