How to Check if String is Capitalized in Javascript
In this tutorial, you will learn how to check if string is capitalized in javascript. Any content in the form of plain text is considered to be a string. A string generally contains a bunch of letters in the form of a text. If those letters are written in capital, then that string is known as capitalized string.
Most of the websites prefer certain data string to be capitalized and this is when it becomes very important to know how to verify if that data string is capitalized or not. This tutorial is definitely going to give you an idea about how you can accomplish that in a simple and easy way.
There are numerous ways to detect whether a string is capitalized or not. But for the sake of simplicity, we will use a strict equality operator (===
) and toUpperCase()
method to accomplish our goal. The toUpperCase()
method converts a given string into a uppercase string.
In the following example, we have one global variable that holds a string. Upon click of a button, we will check whether it is capitalized or not 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“Check”
and for theh1
element, it is“Result”
. - 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>Check</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 inbtnCheck
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. - In the event handler function, we are using a strict equality operator (
===
) and thetoUpperCase()
method to verify whethermyString
is capitalized or not. Depending upon the result of the check, we will assign“Yes”
or“No”
to theresult
variable. - We are displaying the
result
in theh1
element using theinnerText
property.
let btnCheck = document.querySelector("button"); let output = document.querySelector("h1"); let myString = "ABCDEF"; btnCheck.addEventListener("click", () => { let result = myString.toUpperCase() === myString ? "Yes" : "No"; output.innerText = result; });