September 10, 2022

How to Change Negative Number to Positive in Javascript

By Krishnaa JavaScript Questions 0 Comments

In this tutorial, you will learn how to convert negative number to positive number in javascript. You cannot conduct any calculation without numbers. A number is simply an arrangement of digits from 0 to 9. For a newbie developer, it can be a bit tricky to change negative number to positive number.

There are numerous ways to change negative number to positive number. 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 absolute value of a number is given by its distance from zero on the number line, without regard to direction. An absolute value is, to put it simply, the value left over after subtracting any preceding negative sign from a number. The absolute value of -1 is 1.

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 change negative number into a positive number 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, 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 input, btnGet, 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;
});

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