map{ /^$key/ and s/^$key//, $_ } grep( /^$key/, @ta))

##</code><code>##

my @ta = ("a x", "b y", "c z", 'b yyy');
my $key = 'b';
my @values = map / (.*)/, grep /^$key /, @ta;

print "@values\n";

##</code><code>##

my ( $value) = map ...;