Make big numbers readable in Ruby

Quick! How many zeroes are in this number?


Time’s up! Did you get it right?

Large literal numbers may be a cinch for the computer to read, but they aren’t very friendly to human eyes. In this very short screencast, you’ll learn how Ruby makes it easy to write pretty, readable numbers in your code.

Continuing in this series about literals and quoting, let’s talk about large integers.

Quick question: how many zeroes are in this number?


Past a certain size, it’s hard to visually identify the number of digits in a numeric literal. That’s why in written language we usually break the number into groups of digits. For instance, in my US locale we would normally split the number into groups of three digits, with commas:

# 100,000,000,000

Thankfully, we can do something similar in Ruby. Ruby lets us insert underscores anywhere we want in integer literals. So we could rewrite this number like so:


And I think you’ll agree that’s a lot easier to visually parse.

That’s all for today. Happy hacking!