How to Change Lowercase to Uppercase in Javascript
In this tutorial, you will learn how to change lowercase to uppercase in javascript. Sometimes it is very important to change the lowercase string to an uppercase string before sending it for further processing. From a developer perspective, it can be a bit tricky to change lowercase string to an uppercase string.
There are numerous ways to change lowercase string to an uppercase string. We are going to use the simplest approach which involves the usage of toUpperCase()
method. This method will simply convert the string to an uppercase 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 change the lowercase string to an uppercase 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
toUpperCase()
method. As a result, it will change the lowercase string to an uppercase 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 = "i think you are not serious"; output.innerText = myString; btnGet.addEventListener("click", () => { let result = myString.toUpperCase(); output.innerText = result; });