Padding Numbers with JavaScript

JavaScriptJavaScriptBeginner
Practice Now

This tutorial is from open-source community. Access the source code

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

%%%%{init: {'theme':'neutral'}}%%%% flowchart RL javascript(("`JavaScript`")) -.-> javascript/BasicConceptsGroup(["`Basic Concepts`"]) javascript(("`JavaScript`")) -.-> javascript/AdvancedConceptsGroup(["`Advanced Concepts`"]) javascript/BasicConceptsGroup -.-> javascript/variables("`Variables`") javascript/BasicConceptsGroup -.-> javascript/data_types("`Data Types`") javascript/BasicConceptsGroup -.-> javascript/arith_ops("`Arithmetic Operators`") javascript/BasicConceptsGroup -.-> javascript/comp_ops("`Comparison Operators`") javascript/AdvancedConceptsGroup -.-> javascript/template_lit("`Template Literals`") subgraph Lab Skills javascript/variables -.-> lab-28536{{"`Padding Numbers with JavaScript`"}} javascript/data_types -.-> lab-28536{{"`Padding Numbers with JavaScript`"}} javascript/arith_ops -.-> lab-28536{{"`Padding Numbers with JavaScript`"}} javascript/comp_ops -.-> lab-28536{{"`Padding Numbers with JavaScript`"}} javascript/template_lit -.-> lab-28536{{"`Padding Numbers with JavaScript`"}} end

How to Pad a Number in JavaScript

To pad a number in JavaScript, follow these steps:

  1. Open the Terminal/SSH and type node to start practicing coding.
  2. Use the String.prototype.padStart() method to pad the number to the specified length, after converting it to a string.
  3. The padNumber() function below demonstrates this approach.
  4. Pass the number and the desired length as arguments to the function.
  5. 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.

Other JavaScript Tutorials you may like