How to Make Negative Value Positive in Javascript
In this tutorial, you will learn how to make negative value positive in javascript. It is difficult to calculate anything without numbers. A number is made up of a combination of the digits 0 through 9. For a newbie developer, it can be a bit tricky to make negative value positive.
There are numerous ways to make negative value positive. But for the sake of simplicity, we will make use of Math
object. This object contains a lot of methods and properties which can help us in various mathematical operations. One of those methods is the abs()
method.
The abs()
method returns an absolute value of a number. Regardless of the direction, the absolute value of a number can be found by measuring its distance from zero on the number line. Absolute value is the value that persists after removing any prior negative sign from a number. The absolute value of -3 is 3.
In the following example, we have an input field in which we will enter a random negative number. Upon click of a button, we will make negative value positive 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“Get”
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" placeholder="Enter Number"> <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; } 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 the
input
element,button
element, andh1
element using thedocument.querySelector()
method and stored them ininput
,btnGet
, andoutput
variables respectively. - We have attached a
click
event listener to thebutton
element. - In the event handler function, we are storing the value of the
input
element in thenum
variable. - We are calling the
abs()
method to get the absolute ofnum
and storing it in theresult
variable. - We are displaying the
result
in theh1
element using theinnerText
property.
let input = document.querySelector("input"); let btnGet = document.querySelector("button"); let output = document.querySelector("h1"); btnGet.addEventListener("click", () => { let num = input.value; let result = Math.abs(num); output.innerText = result; });