From: Eero Saynatkari <ruby-ml@...>
Date: 2005-11-07T12:02:50+09:00
Subject: Re: programming best practices

swille wrote:
> I have a couple of standard programming questions.  The first is that
> I often like to return true or false in a method when no other return
> value is really needed.  Is that bad form?  I was talking to someone
> the other day who said said something that made me think that maybe it
> was.  For example:
> 
> def login()
>     rc = false
>     begin
>          perform action
>     rescue
>         rc = false
>         some error
>     end
> 
>     return rc
> end
> 
> I like that because it reads well when you use it
> 
> if login
>     do_stuff
> else
>     complain
> end

Whenever it makes sense, do it. If you do not have a use case
like above there is no point in returning a value here it would
seem to be fine. Because in Ruby we can use '?' as a method suffix,
there is really no source of confusion whether you are testing if
someone has logged in (you would use 'login?' for that). In Java,
I imagine, you would use something like 'try_login' instead to
convey the idea of an attempt to do something and a subsequent
test.

Then again, I may be biased. I just tried to suggest Kernel.puts
return true :)

> My second question is this.  I occasionally see stuff like
> if -1 == result
> 
> rather than
> if result == -1
> 
> What, if any, is the benefit of one over the other?

I think this habit is from C and so on; if instead of typing
'if result == -1' you typed 'if result = -1', a possible error
condition would ensue. Many languages and compilers do not issue
a warning about this (lack of a) conditional.

However, when you write 'if -1 == result' there is no possibility
of confusion because the interpreter/compiler would immediately
complain when seeing 'if -1 = result' (can not assign to a literal).

> Thanks


E