Skip to Main Content
Learn to Program, 2nd Edition
book

Learn to Program, 2nd Edition

by Chris Pine
March 2009
Intermediate to advanced content levelIntermediate to advanced
194 pages
4h
English
Pragmatic Bookshelf
Content preview from Learn to Program, 2nd Edition

Another Look at puts

There’s something strange about our favorite method. Take a look at this:

puts 20
puts 20.to_s
puts ​'20'
20
20
20

Why do these three all print the same thing? Well, the last two should, since 20.to_s is '20'. But what about the first one, the integer 20? For that matter, what does it even mean to write the integer 20? When you write a 2 and then a 0 on a piece of paper, you are writing a string, not an integer. The integer 20 is the number of fingers and toes I have; it isn’t a 2 followed by a 0.

Well, here’s the big secret behind our friend puts: before puts tries to write out an object, it uses to_s to get the string version of that object. In fact, the s in puts stands for string; puts really means put string.

This ...

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Start your free trial

You might also like

Learn to Program, 3rd Edition

Learn to Program, 3rd Edition

Chris Pine
The Book of Ruby

The Book of Ruby

Huw Collingbourne

Publisher Resources

ISBN: 9781680500172Errata