I  have an array called @data.  I want to check each element in the array for a value, and if that value exist, I wan to delete it

I could try

@data =~ ~ s/$postalCode//;

### creates an error about private arrays

Maybe this

for my $dat(@data){
$dat=~ s/$postalCode//;
}

The above code does not modify the array at all.  We could create a temporary array and then pop puch and reassign upon going through each element.  That could be time consumming especially if I have 250,000 arrays.  So let's look at map. Charles Galpin has written a pretty simple tutorial on using map here http://articles.techrepublic.com.com/5100-10878_11-1044685.html.

So after reading Charles' article,  I try .

map {s/$postalCode//} @data;

Just to a make sure it works I ran the a line of data through it.  You should always check yoru code on small sets of data. The test and results are below.

Hope this helps in your data munging