This piece of code really has a performance issue, as internally it uses "brutal force". I bench marked this against Ovid's code, this one took 93 seconds when Ovid's only took 6 seconds, for the same array size.

@keys1 = (1..1000000); #array names would be modified to match the plu
+g-in code
for (my $a = 2; $a < 1000000; $a += 2) {
    push @keys2, $a; ##array names would be modified to match the plug
+-in code
}

my $t0 = time();
#plug the code here
print time() - $t0;
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