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| author | Gurusamy Sarathy <gsar@engin.umich.edu> | 1997-02-24 17:29:30 -0500 |
|---|---|---|
| committer | Chip Salzenberg <chip@atlantic.net> | 1997-02-22 02:41:53 +1200 |
| commit | dfdcb7a067c15e57f49dda89180ef92cb98eb798 (patch) | |
| tree | 07849571a37648c2bbb92102205cebd101167593 /pod/perlsub.pod | |
| parent | 55479bb671272502420f9e5f7617b1b0be8544af (diff) | |
| download | perl-dfdcb7a067c15e57f49dda89180ef92cb98eb798.tar.gz | |
Re: Hash key created by subroutine call? (fwd)
On Mon, 24 Feb 1997 06:20:14 MST, Tom Christiansen wrote:
>Considering how frequently this gets asked, how about
>putting it in perlsub?
>
>------- start of forwarded message -------
>From: Rick Smith <ricks@sd.znet.com>
>Newsgroups: comp.lang.perl.misc
>Subject: Hash key created by subroutine call?
>Date: Sat, 22 Feb 1997 21:47:52 -0800
I seem to be in a documental state today.
p5p-msgid: <199702242229.RAA04395@aatma.engin.umich.edu>
Diffstat (limited to 'pod/perlsub.pod')
| -rw-r--r-- | pod/perlsub.pod | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/pod/perlsub.pod b/pod/perlsub.pod index 347d2f8c92..a38d05be25 100644 --- a/pod/perlsub.pod +++ b/pod/perlsub.pod @@ -48,8 +48,15 @@ there's really no difference from the language's perspective.) Any arguments passed to the routine come in as the array @_. Thus if you called a function with two arguments, those would be stored in C<$_[0]> and C<$_[1]>. The array @_ is a local array, but its values are implicit -references (predating L<perlref>) to the actual scalar parameters. The -return value of the subroutine is the value of the last expression +references (predating L<perlref>) to the actual scalar parameters. What +this means in practice is that when you explicitly modify C<$_[0]> et al., +you will be changing the actual arguments. As a result, all arguments +to functions are treated as lvalues. Any hash or array elements that are +passed to functions will get created if they do not exist (irrespective +of whether the function does modify the contents of C<@_>). This is +frequently a source of surprise. See L<perltrap> for an example. + +The return value of the subroutine is the value of the last expression evaluated. Alternatively, a return statement may be used to specify the returned value and exit the subroutine. If you return one or more arrays and/or hashes, these will be flattened together into one large |