perl5.01中引入的given_when(类似于C语言的switch分支语句)

#!/usr/bin/perl -w
use 5.010;
my $dog='Spot';

given ($dog) {
    when (/o/) { say 'The name has an "o"'; continue }
    when (/t/) { say 'The name has an "t"'; continue }
    when (/d/) { say 'The name has an "d"'; continue }
}