December 4, 2021
How to Get Pi Value in Javascript
In this tutorial, you will learn how to get Pi value in javascript. Pi is a constant in mathematics that represents the ratio of the circumference of any circle to the diameter of that circle.
To get the value of Pi, we can make use of the Math
object. This object contains a lot of methods and properties which can help us in various mathematical operations. One of those properties is PI
. The value of Pi is approximately 3.14.
In the following example, we will display the value of Pi on the screen upon click of a button. 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 Pi”
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>Get PI</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. - In the event handler function, we are getting the value of Pi using
PI
property of theMath
object and storing that in theresult
variable. - We only want the
result
to be up to 2 decimal places and that is why we are using thetoFixed()
method and passing 2 as a parameter. - We are displaying the
result
in theh1
element using theinnerText
property.
let btnGet = document.querySelector("button"); let output = document.querySelector("h1"); btnGet.addEventListener("click", () => { let result = Math.PI; result = result.toFixed(2); output.innerText = result; });