How to Get Remainder of Division in Javascript
In this tutorial, you will learn how to get remainder of division in javascript. The remainder of a division is also known as modulus. The division is one of the basic arithmetic operations which every newbie developer should be able to perform without any issue. But it can also be tricky if you are trying to do the division with 2 numbers that are coming from 2 different input fields.
Almost in every programming language, we have a modulus operator (%
) to get the remainder of the division and it is also present in javascript. But since the value present in the input field is of string type, we have to convert it into number type using the Number()
method and then do the calculation using modulus operator (%
).
In the following example, we have 2 input fields in which we will enter 2 random numbers. Upon click of a button, we will get the remainder of the division and display that on the screen. Please have a look over the code example and the steps given below.
HTML & CSS
- We have 4 elements in the HTML file (
div
,input
,button
, andh1
). Thediv
element is just a wrapper for the rest of the elements. - The
innerText
for thebutton
element is“Modulus”
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"> <input type="number" id="firstInput" placeholder="Enter Numerator"> <input type="number" id="secondInput" placeholder="Enter Denominator"> <button>Modulus</button> <h1>Result</h1> </div> <script src="script.js"></script> </body> </html>
.container { text-align: center; } button { margin-top: 10px; padding: 10px 20px; } input { display: block; margin: 10px auto; padding: 10px 20px; } input[type=number]::-webkit-inner-spin-button, input[type=number]::-webkit-outer-spin-button { -webkit-appearance: none; margin: 0; }
Javascript
- We have selected both the
input
elements,button
element, andh1
element using thedocument.querySelector()
method and stored them infirstInput
,secondInput
,btnModulus
, andoutput
variables respectively. - We have attached a
click
event listener to thebutton
element. - In the event handler function, we are passing values of both the
input
elements to theNumber()
method and performing the calculation using the modulus operator (%
). The result is stored in theresult
variable. - We are displaying the
result
in theh1
element using theinnerText
property.
let firstInput = document.querySelector('#firstInput'); let secondInput = document.querySelector('#secondInput'); let btnModulus = document.querySelector('button'); let output = document.querySelector('h1'); btnModulus.addEventListener('click', () =>{ let result = Number(firstInput.value) % Number(secondInput.value); output.innerText = result; });