← Back to1 LOC

Check if a string is a hexadecimal number

Written byPhuoc Nguyen
Category
Validator
Created
10 Jun, 2020
Last updated
13 Oct, 2021
JavaScript version
isHexadecimal.js
const isHexadecimal = (str) => /^[A-F0-9]+$/i.test(str);

// Or
const isHexadecimal = (str) => str.split('').every((c) => '0123456789ABCDEFabcdef'.indexOf(c) !== -1);
TypeScript version
isHexadecimal.ts
const isHexadecimal = (str: string): boolean => /^[A-F0-9]+$/i.test(str);

// Or
const isHexadecimal = (str: string): boolean => str.split('').every((c) => '0123456789ABCDEFabcdef'.indexOf(c) !== -1);
Examples
examples.js
isHexadecimal('123'); // true
isHexadecimal('A1B2C3'); // true
isHexadecimal('#123'); // false

Questions? 🙋

Do you have any questions? Not just about this specific post, but about any topic in front-end development that you'd like to learn more about? If so, feel free to send me a message on Twitter or send me an email. You can find them at the bottom of this page.
I have a long list of upcoming posts, but your questions or ideas for the next one will be my top priority. Let's learn together! Sharing knowledge is the best way to grow 🥷.

Recent posts ⚡

Newsletter 🔔

If you're into front-end technologies and you want to see more of the content I'm creating, then you might want to consider subscribing to my newsletter.
By subscribing, you'll be the first to know about new articles, products, and exclusive promotions.
Don't worry, I won't spam you. And if you ever change your mind, you can unsubscribe at any time.
Phước Nguyễn