Interactive Ruby, also known as IRB, is an interactive command-line tool that allows you to experiment with Ruby code in a REPL (Read-Evaluate-Print-Loop) environment. With IRB, you can type Ruby code directly into the terminal and immediately see the output of that code. This makes it a great tool for testing out small code snippets or exploring Ruby's features.


        IRB is included with Ruby by default, so there's no need to install anything extra to use it. To start IRB, simply open a terminal and type "irb". This will launch the IRB prompt, which looks like this:

irb(main):001:0>

From here, you can type in Ruby code and see the results immediately. For example, you could type:
irb(main):001:0> 2 + 2
=> 4

And you would see the output 4 immediately.

IRB also has some useful features that make it a great tool for exploring Ruby. For example:
  • You can use the up and down arrow keys to scroll through previous commands.
  • You can use the Tab key to autocomplete variable and method names.
  • You can use the help command to see a list of available IRB commands and their descriptions.
Overall, IRB is a great tool for experimenting with Ruby code and exploring its features in an interactive and immediate way.