the "return" in a module

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Probably a dumb question, but I have been assuming I know the answer...

I noticed that some of my modules have a "return 1" near the top of the file, while others, I had put it as the last line. (I am still a Perl newbie)

Does this affect package globals or subroutine definitions?

Is there a good standard?

Note that I am not asking where to put my subs() though ;-)

ps

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Comment on the "return" in a module

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Re: the "return" in a module by Juerd (Abbot) on Mar 09, 2002 at 01:59 UTC
Is there a good standard? It's very common to simply end with `1;`. It's needed, because perl uses the last expression that was evaluated to determine if the module was loaded correctly. When it's not there, but the module still works, that means the last expression was true, but it's considered bad style to depend on that. I've also seen people use strings over there (`q/Murphy's law is recursive. Washing your car to make it rain doesn't work./;`), or `42;`, and other values representing truth. 44696420796F7520732F2F2F65206F 7220756E7061636B3F202F6D736720 6D6521203A29202D2D204A75657264	[reply]
Re: the "return" in a module by mpeppler (Vicar) on Mar 09, 2002 at 00:56 UTC
AFAIK the placement of the return 1; (or just 1;) in the module file makes no difference. Michael	[reply]
Re (tilly) 2: the "return" in a module by tilly (Archbishop) on Mar 09, 2002 at 03:09 UTC
Actually it can make a difference in two ways. The first is that if you put a return before some code that you want executed, it won't be because you returned. The second is that if you just use a true value but don't return, and accidentally put some executable code after it (eg a variable initialization) with a false value, then your module will fail to load. Both should be obvious if you are bitten by them. But I like putting the true return value at the end anyways.	[reply]
Re: Re (tilly) 2: the "return" in a module by mpeppler (Vicar) on Mar 11, 2002 at 14:07 UTC
That makes sense - thanks. Michael	[reply]
Re: the "return" in a module by theguvnor (Chaplain) on Mar 09, 2002 at 05:13 UTC
Not that it's yet a concern, I believe (but could not find the evidence!) it was announced that in Perl 6 modules will no longer be required to return true. (And where is that Exegesis 4 anyway? ;^) ..Guv	[reply]