How to Check if String Length Greater Than 0 in Javascript
In this tutorial, you will learn how to check if string length greater than 0 in javascript. There are certain primitive types in javascript and string is one of them. As the name suggests, any variable that holds a plain text as its value is considered to be of string type.
There are numerous ways to check if a string length greater than 0. But for the sake of simplicity, we will use length
property and ternary operator (?
). The length
property returns the length of the string. If the string is empty, then it will return 0. The ternary operator is also known as the conditional operator which acts similar to the if-else statement.
In the following example, we have one global variable that holds a string. Upon click of a button, we will check if the string length greater than 0 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 the
length
property and ternary operator (?
) to check ifmyString
length greater than 0. 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 = "Hello World"; btnCheck.addEventListener("click", () => { let result = myString.length > 0 ? "Yes" : "No"; output.innerText = result; });