You can't pass an array to a subroutine! You can pass the values of an array (which is what you did) or a reference to an array. Consider this: 

sub foo {
 print "@_\n";
 push @_, 99;
}

@a = (1,2,4);
foo(@a, 666)

[download]

Now what's Perl supposed to do with this? Keep in mind that the foo() did not get two parameters, it got FOUR. The three elements of @a and the 666. The first three modifiable, the last readonly. No array was passed.

The docs talk about things like foo( $a[99]) and foo( $h{new_key}), where in an old version the @a would be expanded and the 'new_key' key added into the %h upon calling the subroutine, while in the new versions this is only done if necessary.

This is consistent with things like if (defined($a[99]){... versus $a[99] = 0;.

Jenda
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In reply to Re^2: perlsub question.. by Jenda
in thread perlsub question.. by Anonymous Monk

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