The Book of Ruby

Case Statements

When you need to take a variety of different actions based on the value of a single variable, multiple if..elsif tests are verbose and repetitive.

A neater alternative is provided by a case statement. This begins with the word case followed by the variable name to test. Then comes a series of when sections, each of which specifies a “trigger” value followed by some code.

This code executes only when the test variable equals the trigger value:

case.rb

case( i )
   when 1 then puts("It's Monday" )
   when 2 then puts("It's Tuesday" )
   when 3 then puts("It's Wednesday" )
   when 4 then puts("It's Thursday" )
   when 5 then puts("It's Friday" )
   when (6..7) then puts( "Yippee! It's the weekend! " )
   else puts( "That's not a real day!" )
end

Constants ...