At 2:19 PM +0100 4/23/09, Tony Marston wrote:
"tedd" <tedd.sperling@xxxxxxxxx> wrote in message
> It's called "Structured programming" -- one way in and one way out of a
function.
There are, of course, exceptions where it might help others reviewing your
code to see what's going on, such as returning a null value if the
argument(s) provided are not suitable. But normally the rule is, do not
provide an exit from a function in more than one place.
There is no such "rule", it is a matter of personal preference. As a
previous poster has already said, if you want to leave a function early and
ignore all subsequent processing it is easier to understand if you return
immediately rather than have a mechanism to jump over the remaining code to
a single return point. In the good old days we used to use the GOTO in COBOL
to jump to the exit point, but then people found a way to abuse GOTO in very
imaginatve ways.
The "benefit" is easier to read code.
I think that an immediate return is easier to read, but what do I know -
I've only been programming for 30 years.
--
Tony Marston
Tony:
Don't get your panties in a knot. :-)
I have 44 years of programming under my belt, so what? However, I
wish I could remember everything I learned during that time.
But what I do remember is there's a school of thought called
"Structured Programming" that has a doctrine in which every function
should have only one entry and exit point.
Now maybe you want to argue with that concept, that's fine -- but the
point remains this is a "rule" under "Structured Programming". That's
history.
Now, I usually follow that rule for I have learned from experience
that in most cases, it is easier to read what is going on in a
function if you only have one exit.
As I said in my post, there are of course exceptions. There are times
that requiring a function to have a single exit point will
unnecessarily create code that's hard to read -- so doing it
differently is something to consider in those cases. If you want to
have an immediate exit point in your functions and that makes your
code more readable, then that's fine and I'm not arguing that point.
However, I am saying (after years of reading other people's code) it
is generally much easier to read code that follows "Structured
Programming" than it is to read code that doesn't.
Cheers,
tedd
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