Re: Parameters, subs and the shift function

Parameters to a function get flattened to a single list. If you call a sub as test (3, @a, @b), then inside test you can't distinguish what came from @a and what from @b. If you want to pass entire arrays, you will have to pass references, and deal with references in the function.

    sub test {
        my $number = shift;
        my @array1 = @{+shift};  # Shift off the reference, and derefe
+rence it
        my @array2 = @{+shift};
        # Do your stuff
    }
    test (2, \@a, \@b);
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Abigail

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Re: Re: Parameters, subs and the shift function by monktim (Friar) on Aug 19, 2003 at 14:42 UTC
Abagail-II, what is the signifigance of the + in the shift statements? Why is this a good thing to do? `my @array1 = @{+shift}; my @array2 = @{+shift};` [download] Thanks, Tim	[reply] [d/l]
Re: Parameters, subs and the shift function by Abigail-II (Bishop) on Aug 19, 2003 at 14:55 UTC
Run it under strict, and try it without the `+`. The error message you get will enlighten you. Abigail	[reply]
Re: Re: Parameters, subs and the shift function by monktim (Friar) on Aug 19, 2003 at 15:02 UTC
Ahh, thank you. I'm a little embarrassed. I never dereferenced a builtin like shift only user defined functions. `Global symbol "@shift" requires explicit package name at noname5.pl li +ne 5. Global symbol "@shift" requires explicit package name at noname5.pl li +ne 6. Execution of noname5.pl aborted due to compilation errors.` [download]	[reply] [d/l]