http://qs1969.pair.com?node_id=114909

cyberscribe has asked for the wisdom of the Perl Monks concerning the following question:

I am attempting to merge two arrays and not succeeding. I believe it has to do with how Perl references arrays and deals with functions ("subs") and how I do not understand either very well.

see the following:

#start code (such as it is) sub merge { my (@array1,@array2) = @_; $array1_size = @array1; $array2_size = @array2; for($i=0;$i<$array1_size;$i++) { if(!lookup(@array1[$i],$array2)) { push(@array2,($array1[$i])); } else { break; } } return $array2; } sub lookup { my($value,$array) = @_; $return = FALSE; $array_size = @array; for($i=0;$i<$array_size;$i++) { if($value eq @array[$i]) { $return = TRUE; } } return $return; } @array1 = split(/ /,"a b c d e"); @array2 = split(/ /,"c d e f"); @merged_array = merge(@array1,@array2); #end code

merged_array should now be {"a","b","c","d","e","f"}. Instead I get an infinite loop.

I've managed to squeak by coding perl scripts to do nslookups and DBI data access, enjoying how the language can make quick work of messy strings. But I obviously don't understand the "finer points" of the language. Any pointers (pun intended?) appreciated.

-RP