http://qs321.pair.com?node_id=239379


in reply to Use an array slices

Have you thought about what happens when you add the tenth (i.e. '10') branch?

-Blake

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Re: Re: Use an array slices
by nite_man (Deacon) on Feb 28, 2003 at 14:38 UTC
    This decision doesn't have pretensions on absolutly universality. I have just had a case with fixed choises. If I will add the tenth branch, I will add a choice for it. 
    #!/usr/bin/perl -w

use strict;

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[reply]
[d/l]
      I assume that case would look something like this: 
      #!/usr/bin/perl -wT
use strict;

my $value = 10;

SWITCH: for ($value) {
    /0/  && do {print "ZERO\n"; last; };
    /1/  && do {print "ONE\n";  last; };
    /10/ && do {print "TEN\n";  last; };
                print "NONE OF THE ABOVE\n";
}

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      Can you guess what the output is? Run it and find out.

      -Blake

[reply]
[d/l]

        It produces the ZERO message :) Matching the whole string produces better results:

        #!/usr/local/bin/perl

use strict;
use warnings;

my $value = 10;
SWITCH: for ($value) {
    /^0\z/  && do {print "ZERO\n"; last; };
    /^1\z/  && do {print "ONE\n";  last; };
    /^10\z/ && do {print "TEN\n";  last; };
                print "NONE OF THE ABOVE\n";
}

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[reply]
[d/l]
        Well, "ZERO". But that's easily solvable (although it looks less pretty): 

        #!/usr/bin/perl -wT
use strict;

my $value = 10;

SWITCH: for ($value) {
    /^0$/  && do {print "ZERO\n"; last; };
    /^1$/  && do {print "ONE\n";  last; };
    /^10$/ && do {print "TEN\n";  last; };
                print "NONE OF THE ABOVE\n";
}

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        Leonid Mamtchenkov

[reply]
[d/l]

In Section Cool Uses for Perl