Pass by ref an array weirdness

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

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•Re: Pass by ref an array weirdness by merlyn (Sage) on Dec 05, 2002 at 16:36 UTC
`print "@$_[1]\n"; # Does Not work, why ?` [download] Because it's parsed as `@{$_}[1]` - a slice (one element long, usually broken) of the array pointed to by the `$_` variable. The syntax is very predictable, once you learn the rules in perlref (and perlreftut). -- Randal L. Schwartz, Perl hacker Be sure to read my standard disclaimer if this is a reply.	[reply] [d/l] [select]
Re: Pass by ref an array weirdness by sauoq (Abbot) on Dec 05, 2002 at 17:56 UTC
Your question has been answered but you have another issue that will eventually cause problems for you. Your sub, "func" is defined with an empty prototype. `sub func() {` [download] Later, you get around the problems caused by the prototype by calling the sub with an explicit `&`. `&func(\@x, \@y);` [download] That's a terrible habit to get into. Prototypes in Perl aren't anything like prototypes in other languages and you shouldn't use them at all unless you really understand what they are for and can pick out the special case where they make sense. It would be better to define "func" as `sub func { ... }` [download] and call it like `func(\@x, \@y);` [download] -sauoq "My two cents aren't worth a dime.";	[reply] [d/l] [select]
Re: Pass by ref an array weirdness by bronto (Priest) on Dec 05, 2002 at 17:08 UTC
When you are dereferencing, it's always safer (but more bothering to type, I know) to explicitly include braces, as you did with `$_[0]`; this way you will be sure that the code really does what you asked it to do. Note that not always "what you asked it to do" is the same as "what you wanted him to do" `;-)` Ciao! `--bronto` # Another Perl edition of a song: # The End, by The Beatles END { $you->take($love) eq $you->make($love) ; }	[reply] [d/l]