How to Convert Negative Value into Positive in Javascript

In this tutorial, you will learn how to convert negative value into positive in javascript. There is no computation that can be done without numbers. The digits 0 through 9 are combined to form a number. For a newbie developer, it can be a bit tricky to convert negative value into positive.

There are numerous ways to convert negative value into 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. The distance of a number from zero on the number line, independent of direction, yields the absolute value of the number. In plain English, an absolute value is what remains after removing any preceding negative sign from a number. The absolute value of -2 is 2.

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 convert negative value into a 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 (divinputbutton, and h1). The div element is just a wrapper for the rest of the elements.
  • The innerText for the button element is “Get” and for the h1 element, it is “Result”.
  • We have done some basic styling using CSS and added the link to our style.css stylesheet inside the head element.
  • We have also included our javascript file script.js with a script 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, and h1 element using the document.querySelector() method and stored them in inputbtnGet, and output variables respectively.
  • We have attached a click event listener to the button element.
  • In the event handler function, we are storing the value of the input element in the num variable.
  • We are calling the abs() method to get the absolute of num and storing it in the result variable.
  • We are displaying the result in the h1 element using the innerText 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;
});