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

Posted by avremel
avremel
8,448 Points

Ruby operators code challenge

<h1>This is the challeng: </h1> Modify the "valid_command?" method to return true when passed the following values: "y", "yes", "Y", or "YES".

Here is what I tried:

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

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

Why is this not working?

Bisrat Teshome
Bisrat Teshome
1,028 Points

Removing the parenthesis (since you already used double quotes) will solve the problem.

def valid_command? (command)

if command == "y" || command == "yes" || command == "Y" || command == "YES"

return "true"

end

end

5 Answers

Andrew Stelmach
Andrew Stelmach
12,583 Points

You got most of it right. I don't have the depth of knowledge to guide you towards an answer, but I know what it should be:

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

Personally, I don't know why you can't just say 'return' instead of 'return true', because I would have thought that 'return' would return 'true' i.e. the method would evaluate to true.

Maybe someone can enlighten us.

EDIT: the code is 'DRY-ist' as:

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

Personally, this is how I would write it - it's readable enough for most developers.

avremel
avremel
8,448 Points

Thanks for the quick response

Wilfredo Casas
Wilfredo Casas
6,174 Points

are these '||' the same as &&?

Andrew Stelmach
Andrew Stelmach
12,583 Points

Wilfredo Casas , no; it means 'or'.

codebully
codebully
2,306 Points
codebully
codebully
2,306 Points

You can DRY this up with as well:

def valid_command?(command)
  if (command.downcase == "y") || (command.downcase == "yes")
    return true
  end 
end
Wilfredo Casas
Wilfredo Casas
6,174 Points

are these '||' the same as &&?

adrian silva
adrian silva
4,959 Points
adrian silva
adrian silva
4,959 Points

i used the case and when condition but that didnt work i just want to know why or is it just how it is ? def valid_command?(command) case command when command == "y" return true when command == "yes" return true when command == "Y" return true when command == "YES" return true end end

Sandra Hogan
Sandra Hogan
8,657 Points
Sandra Hogan
Sandra Hogan
8,657 Points

Wilfredo Casas '||' and '&&' are 2 different symbols. The pipes( || ) mean 'or' and the '&&' mean 'and'