my @x = (1..10);
foreach (@x) {
    $_ += 100;
}
print "@x"; 

OUTPUT: 
101 102 103 104 105 106 107 108 109 110

##</code><code>##


my @x = (1..10);
foreach my $element (@x) {
    $element += 100;
}
print "@x"; 

OUTPUT: 
101 102 103 104 105 106 107 108 109 110

##</code><code>##

 map {$_ += 100} @x;

(yields same output and alters @x as does...)
 
$_ += 100 for @x; 

in case you wondered... :)