How to Trim Last Character if Comma in Javascript
In this tutorial, you will learn how to trim last character if comma in javascript. 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 trim the last character if comma.
There are numerous ways to trim the last character if comma. 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 trim the last character if comma 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
, andh1
). Thediv
element is just a wrapper for the rest of the elements. - The
innerText
for thebutton
element is“Trim”
. - We have done some basic styling using CSS and added the link to our
style.css
stylesheet inside thehead
element. - We have also included our javascript file
script.js
with ascript
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>Trim</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 andh1
element using thedocument.querySelector()
method and stored them inbtnTrim
andoutput
variables respectively. - We have attached a
click
event listener to thebutton
element. - We have a global variable
myString
which holds a string as its value. - We are displaying the original string in the
h1
element using theinnerText
property. - In the event handler function, we have
regex
variable that holds a regex pattern/,$/g
as its value. - We are calling
replace()
method and passingregex
and empty string as parameters. As a result, it will trim the last character if comma. The new string returned by this method will be stored in theresult
variable. - We are displaying the
result
in theh1
element using theinnerText
property.
let btnTrim = document.querySelector("button"); let output = document.querySelector("h1"); let myString = "Chris just moved in.,"; output.innerText = myString; btnTrim.addEventListener("click", () => { let regex = /,$/g; let result = myString.replace(regex, ""); output.innerText = result; });