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Ruby Ruby Operators and Control Structures Logical Operators The Or (||) Operator

Posted by A X
A X
12,842 Points

Not Understanding the Double End or the ? in the Code Challenge

Challenge: Modify the valid_command? method to return true when passed the following values: "y", "yes", "Y", or "YES".

Although I solved this challenge correctly, I don't understand why we need to use end twice as well as I don't understand what the ? is used for...is it just part of the variable name here? Jason used .even? and .odd? in the video prior without explaining what the ? was for. 

def valid_command?(command)
  if (command == "y") || (command == "yes") || (command == "Y") || (command == "YES")
    return true
  end 
end

2 Answers

Kourosh Raeen
Kourosh Raeen
23,733 Points
Kourosh Raeen
Kourosh Raeen
23,733 Points

The question mark is part of the method name. It is not necessary but it is a code convention indicating that the method returns a boolean value. As for the end keyword, it is once to indicate the end of the if block and once to indicate the end of the method.

Allison Hanna
Allison Hanna
36,222 Points
Allison Hanna
Allison Hanna
36,222 Points

Just as a fun note, you can also write only two cases instead of four if you use command.upcase (with "Y" or "YES") or command.downcase (with "y" or "yes").