July 22, 2022

How to Insert Comma After Every Character in Javascript

By Krishnaa JavaScript Questions 0 Comments

In this tutorial, you will learn how to insert comma after every character in javascript. A string is made up of many characters and a comma (,) in an English sentence is used after an introductory clause or phrase. For a newbie developer, it can be a bit tricky to insert comma after every character.

There are numerous ways to insert comma after every character. We are going to use the simplest approach which involves the usage of the regex pattern as well as replace() method. The replace() method searches the string for a particular value or a regex pattern and it returns a new string with the replaced values.

In the following example, we have one global variable that holds a string. Upon click of a button, we will insert comma after every character and display the result on the screen. Please have a look over the code example and the steps given below.

HTML & CSS

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">

<head>
  <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">
  <title>Document</title>
</head>

<body>

  <div class="container">    
    <button>Add</button>
    <h1>Result</h1>
  </div>

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

</html>

.container {        
    text-align: center;
}

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

Javascript

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 a global variable myString which holds a string as its value.
We are displaying myString in the h1 element using innerText property.
We have attached a click event listener to the button element.
In the event handler function, we are using replace() method with a regex to match 1 character at a time and inserting a comma immediately after that. The $& is a backreference to the whole match. 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 myString = `abcdefghijklmnop`;
output.innerText =  myString;
 
btnAdd.addEventListener("click", () => {  
  let result = myString.replace(/.{1}/g, '$&,');;
  output.innerText = result;
});

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