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

I would like to know of the two inlined subroutine constants below which would be the correct perl idiom. 
sub BUFFER { 2048 }

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or 
sub BUFFER () { 2048 }

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also... what is the correct term for the above? Am I correct in saying inlined subroutine contstant??
~tango mike

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Re: subroutine constants
by suaveant (Parson) on Sep 21, 2001 at 00:30 UTC
    The best way is 
    use constant BUFFER => 2048;

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                    - Ant
                    - Some of my best work - Fish Dinner

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[d/l]
      perhaps I was unclear.....?
      I know of the various other methods of creating constants. I would just like to know the difference between the two used above as they both compile the same in my script. 
      #!/usr/bin/perl -w

use strict;

sub BUFFER { 2048 }

print BUFFER, "\n";

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      and 
      #!/usr/bin/perl -w

use strict;

sub BUFFER () { 2048 }

print BUFFER, "\n";

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[d/l]
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        I don't know that there is much real difference other than one will fail if you try to pass it arguments and one won't (I think)... in general though, I believe use Constants is better since it does some behind the scenes work and is done compile time... if you are going to do it the hard way, probably sub BUFFER () { 2048 } is the better way to go.

                        - Ant
                        - Some of my best work - Fish Dinner

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[d/l]
        sub BUFFER () { 2048 }
        implements prototyping, perl's somewhat limited way of compile-time subroutine arg checking.

        Doing this like shown above (the empty prototype) indicates that the sub takes no args, and if you try to pass it any args, it will produce a compile time error.

        I am also somewhat sure that the difference in your compilation would be very subtle, if much different at all.

        These as far as I know are considered inline subroutine constants.
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[d/l]

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