You are trying to show us your arrays with pseudo-perl starting @array = ..., but the rest is not valid perl, and it's not clear where elements start or end, or even if this is a one dimensional array or not.

How about showing the contents of the arrays using Data::Dumper's Dumper(\@array) output instead?

Rereading the question, I think I understand. The comparison code you are using is designed to detect differences in either array. To just find the ones unique to @ICUNAV, you would use just @union in your first loop, and then loop through @ICUNAV looking for elements for which no key exists in the hash.