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Write the best switch function?

I am new to Ruby.
How can I write this function better? I can use a hash table instead.

def readable_status(status)
  if status == "1" 
    return "go"
  end
  if status == "2"
    return "stop"
  end
  if status == "3"
    return "die"
  end
end
+3


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5 answers


If you want to use hash (as per your question), you can do:



def readable_status(status)
   readable = { "1" => "go", "2" => "stop", "3" => "die" }
   readable[status] || "default value"
end
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What about



def readable_status(status)
  %w{go stop die}[status.to_i - 1]
end
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sure just use

def readable_status(status)
    m = {'1' => 'go', '2' => 'stop', '3' => 'die'}
    m[status]
end

you can do this oneliner if you like:

...
{'1' => 'go', '2' => 'stop', '3' => 'die'}[status]
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I was having unsuccessful attempts with Hash-es for this problem due to a suboptimal specification that was provided to me (which means: changing the business specification during development).

Hashes are fine as long as you don't need to write something more complex than a single value. If you need to change these single values ​​to methods, you must rewrite everything, since the hash takes the value of the methods, invoking them when the hash is determined. And if the method later returns a value, the hashes will not be changed.

And it remains readable in English :-)

def readable_status(status)
  case status 
    when "1" then "go" end
    when "2" then "stop" end
    when "3" then "die" end
  end
end
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If a hash is defined inside a method, the hash (and every line in it) is recreated every time the method is called. Defining a constant prevents this from happening; using a method to access values ​​is still flexible as @Phrogz said.

READABLE_STATUS_TABLE = {'1'=>'go', '2'=>'stop', '3'=>'die'}

def readable_status(status)
  READABLE_STATUS_TABLE[status]
end
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