Книга: Fedora™ Unleashed, 2008 edition

foreach

foreach

The foreach construct performs a statement block for each element in a list or array:

@names = ("alpha","bravo","charlie");
foreach $name (@names) {
 print "$name sounding off!n";
}

The loop variable ($name in the example) is not merely set to the value of the array elements; it is aliased to that element. That means if you modify the loop variable, you're actually modifying the array. If no loop array is specified, the Perl default variable $_ may be used:

@names = ("alpha","bravo","charlie");
foreach (@names) {
 print "$_ sounding off!n";
}

This syntax can be very convenient, but it can also lead to unreadable code. Give a thought to the poor person who'll be maintaining your code. (It will probably be you.)

Оглавление книги