Always pass the radix to parseInt

Written byPhuoc Nguyen

Tags

JavaScript

Created

23 Feb, 2021

The `parseInt` method takes two parameters:

parseInt(value, radix);

The second parameter specifies the current numeral system. In the case it's not specified, then it will be set automatically based on the value. If the value starts with `0x` or `0X`, then the radix is 16 (hexadecimal). In other cases, the radix is 10 (decimal).

In the older versions of JavaScript, if the string starts with `0` then the radix is set as 8 (octal).

parseInt('0xF'); // 15
parseInt('0XF'); // 15
parseInt('0xF', 16); // 15

parseInt('0xF', 10); // 0

Since the method could be implemented differently in different versions of JavaScript and browsers, it's recommended to pass the radix number.

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 🥷.

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

Always pass the radix to parseInt

Questions? 🙋

Recent posts ⚡

Newsletter 🔔