Aggregate pattern: Difference between revisions

Revision as of 14:10, 30 August 2007

Revision as of 19:51, 17 October 2007

Line 13:

Members of a common [[Subclass (computer science)|subclass]] are each known to have certain [[Method (computer science)|method]]s. These methods return information about the state of that particular [[object (computer science)|object]]. It does happen that an application is concerned with an aggregation, or amalgamation, of data from several object of the same type. This leads to code being repeated around the program:

(Perl example)

<source lang="perl">

my $subtotal;

foreach my $item (@cart) {

$subtotal += $item->query_price();

}

my $weight;

foreach my $item (@cart) {

$weight += $item->query_weight();

}

# and so on

</source>