Reversing Numbers in JavaScript

Introduction

In this lab, we will explore the concept of reversing a number in JavaScript. We will learn how to use built-in methods such as split(), reverse(), and join() to achieve this task. By the end of this lab, you will have a deeper understanding of how to manipulate numbers in JavaScript.

Skills Graph

Reversing a Number

To reverse a number using JavaScript, you can use the reverseNumber() function with the following steps:

1. Convert the number n to a string using Object.prototype.toString().
2. Use String.prototype.split(), Array.prototype.reverse() and Array.prototype.join() to get the reversed value of n as a string.
3. Convert the string back to a number using parseFloat().
4. Preserve the sign of the number using Math.sign().

Here's the code for the reverseNumber() function:

const reverseNumber = (n) =>
  parseFloat(`${n}`.split("").reverse().join("")) * Math.sign(n);

You can test the function with these examples:

reverseNumber(981); // 189
reverseNumber(-500); // -5
reverseNumber(73.6); // 6.37
reverseNumber(-5.23); // -32.5

Summary

Congratulations! You have completed the Reverse Number lab. You can practice more labs in LabEx to improve your skills.