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| -rw-r--r-- | ruby.html.markdown | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/ruby.html.markdown b/ruby.html.markdown index 6743de6b..bdad4d06 100644 --- a/ruby.html.markdown +++ b/ruby.html.markdown @@ -419,6 +419,19 @@ breakfast, lunch, dinner = foods breakfast # 'pancake' dinner # 'quesadilla' +# By convention, all methods that return booleans end with a question mark +5.even? # false +5.odd? # true + +# And if a method ends with an exclamation mark, it does something destructive +# like mutate the receiver. Many methods have a ! version to make a change, and +# a non-! version to just return a new changed version +company_name = "Dunder Mifflin" +company_name.upcase #=> "DUNDER MIFFLIN" +company_name #=> "Dunder Mifflin" +company_name.upcase! # we're mutating company_name this time! +company_name #=> "DUNDER MIFFLIN" + # Define a class with the class keyword class Human |