Pad Numbers in JavaScript | Programming Tutorial

Introduction

In this lab, we will be exploring the concept of padding a given number to a specified length using JavaScript. We will be using the String.prototype.padStart() method to pad the number and convert it to a string. Through this lab, you will gain a better understanding of how to manipulate strings and numbers in JavaScript.

Skills Graph

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How to Pad a Number in JavaScript

To pad a number in JavaScript, follow these steps:

Open the Terminal/SSH and type node to start practicing coding.
Use the String.prototype.padStart() method to pad the number to the specified length, after converting it to a string.
The padNumber() function below demonstrates this approach.
Pass the number and the desired length as arguments to the function.
The function returns the padded number as a string.

const padNumber = (n, l) => `${n}`.padStart(l, "0");

Example usage:

padNumber(1234, 6); // '001234'

Summary

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