From: dblack@...
Date: 2007-02-19T23:20:24+09:00
Subject: Re: return statement

Hi --

On Mon, 19 Feb 2007, Derek Teixeira wrote:

>> Return means "we are done".
>>
>> Sometimes when you write a method (I don't know the jargon used in
>> that book, it may be function, or subroutine, or procedure, ...) you
>> know somewhere in the middle that _if the code reached that point_ we
>> do not need to do anything else. For instance, see this method that
>> says where the given number is positive:
>>
>>    def is_positive?(n)
>>      if n > 0
>>        return true
>>      end
>>      return false
>>    end
>>
>> That method can be written in different ways, but to depict the
>> meaning of return: if n is greater than 0, you already know the
>> answer, so in that point you indicate there's no need to execute more
>> code, you're ready to give the answer: true. If the execution reaches
>> that point, the following executable line "return false" will be
>> ignored altogether, execution is halted.
>>
>> Return in addition accepts a value to be returned (true/false in the
>> example), which is considered to be the _result_ of that method call
>> in such case.
>
>  So you are saying that it basically saves the confusion of elsif's and
> it just makes more sense.. in your example you could have easily written
>
> def is_positive?(n)
> if n > 0
>       answer= true
>    elsif
>    n<0
>       answer= false
> end
>
> Right? but that just looks sloppy and could really get confusing if i
> had more lines of code.. am i getting it right?

Well, in that particular case, I would just do:

   def is_positive?(n)
     n > 0
   end

You definitely don't need the temporary variable (answer), and in fact
you don't need to code the true/false return values because > will
already give you one or the other.


David

-- 
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