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Diffstat (limited to 'pod/perlsub.pod')
| -rw-r--r-- | pod/perlsub.pod | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/pod/perlsub.pod b/pod/perlsub.pod index 3a5357392c..bfab0fe81e 100644 --- a/pod/perlsub.pod +++ b/pod/perlsub.pod @@ -581,6 +581,28 @@ Perl will print This is a test only a test. The array has 6 elements: 0, 1, 2, undef, undef, 5 +Note also that when you C<local>ize a member of a composite type that +B<does not exist previously>, the value is treated as though it were +in an lvalue context, i.e., it is first created and then C<local>ized. +The consequence of this is that the hash or array is in fact permanently +modified. For instance, if you say + + %hash = ( 'This' => 'is', 'a' => 'test' ); + @ary = ( 0..5 ); + { + local($ary[8]) = 0; + local($hash{'b'}) = 'whatever'; + } + printf "%%hash has now %d keys, \@ary %d elements.\n", + scalar(keys(%hash)), scalar(@ary); + +Perl will print + + %hash has now 3 keys, @ary 9 elements. + +The above behavior of local() on non-existent members of composite +types is subject to change in future. + =head2 Passing Symbol Table Entries (typeglobs) [Note: The mechanism described in this section was originally the only |