Jay McGavrenTreehouse Teacher
When you want to write a multi-line program that you're going to keep around and run many times, you want to write an
.rb file in your editor and run it with the
ruby command. But when you are just experimenting and trying out code, you can use
irb. It lets you run the same statement many different ways, and see what the results are each time.
There's never anything you have to use
irb for. But you can choose to use it when you're just experimenting.