Everything is an Object
In Ruby even a plain number or nil is a real object you can call methods on.
Everything is an object in Ruby: every value you touch is a real object that carries its own methods, including plain numbers, nil, true and false, and even classes themselves. There are no second-class “primitives” sitting outside the object system the way there are in some other languages. That is why the number 5 can answer messages directly: you can write 5.times { puts "hi" } to repeat something five times, ask (-5).abs to get 5 back, or call nil.to_s and get an empty string. It is a big part of what people mean when they say Ruby is built to "Optimize for programmer happiness": the rules stay the same everywhere, so there is less to memorize.
Related: "Optimize for programmer happiness" · Monkey Patching · Duck Typing
Sources
Sources
- About Ruby (ruby-lang.org), “In Ruby, everything is an object” and the
5.timesexample: https://www.ruby-lang.org/en/about/