How to Convert Uppercase to Lowercase in Javascript
In this tutorial, you will learn how to convert uppercase to lowercase in javascript. Sometimes it is very important to convert the uppercase string into a lowercase string before sending it for further processing. From a developer perspective, it can be a bit tricky to convert uppercase string to a lowercase string.
There are numerous ways to convert uppercase string to a lowercase string. We are going to use the simplest approach which involves the usage of toLowerCase()
method. This method will simply convert a string to a lowercase string and return a new string.
In the following example, we have one global variable that holds a string. Upon click of a button, we will convert the uppercase string to a lowercase string 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“Get”
. - 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>Get</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 inbtnGet
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 are calling
toLowerCase()
method. As a result, it will convert the uppercase string to a lowercase string. 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 btnGet = document.querySelector("button"); let output = document.querySelector("h1"); let myString = "KEEP THAT THING GOING"; output.innerText = myString; btnGet.addEventListener("click", () => { let result = myString.toLowerCase(); output.innerText = result; });