As you say, the slice method is faster again. I will be using it from now on. Thanks.

use Benchmark;

@a= (0..100,0..100);

$mine = <<'CODE';
my %hash;
@hash{$_}++ for @a;
@a = keys %hash;
CODE

$yours1 = <<'CODE';
my %hash;
@hash{@a} = ();
@a = keys %hash;
CODE

$yours2 = <<'CODE';
my %hash;
@hash{@a} = @a;
@a = values %hash;
CODE

$his = <<'CODE';
my %hash;
map { $hash{$_}=1 } @a;
@a = keys %hash;
CODE

timethese ( 10000, { 'mine'   => $mine, 
                     'yours1' => $yours1,
                     'yours2' => $yours2, 
                     'his'    => $his 
                   } );

__END__
C:\>perl test.pl
Benchmark: timing 10000 iterations of his, mine, yours1, yours2...
       his: 17 wallclock secs (17.03 usr +  0.00 sys = 17.03 CPU) @ 58
+7.20/s (n=10000)
      mine: 15 wallclock secs (15.05 usr +  0.00 sys = 15.05 CPU) @ 66
+4.45/s (n=10000)
    yours1: 12 wallclock secs (11.76 usr +  0.00 sys = 11.76 CPU) @ 85
+0.34/s (n=10000)
    yours2: 15 wallclock secs (14.78 usr +  0.00 sys = 14.78 CPU) @ 67
+6.59/s (n=10000)

C:\>
[download]

cheers

tachyon

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