perlfaq nodetype
faq_monk
<P>
Use a hash. Here's code to do both and more. It assumes that each element
is unique in a given array:
<P>
<PRE> @union = @intersection = @difference = ();
%count = ();
foreach $element (@array1, @array2) { $count{$element}++ }
foreach $element (keys %count) {
push @union, $element;
push @{ $count{$element} > 1 ? \@intersection : \@difference }, $element;
}
</PRE>
<P>