perl的foreach循环的坑

 1 my %hash;
 2  
 3 %hash = ("小明"=>{'语文'=>50, '数学'=>60},
 4         "小刚"=>{'语文'=>80, '数学'=>90});
 5  
 6 foreach my $key ( keys %hash )
 7 {
 8     print "$key:\n";
 9     my %subhash = $hash{$key};
10     foreach my $subkey ( keys %subhash )
11     {
12         print "\t$subkey => $subhash{$subkey}\n";
13     }
14 }

my %hash;
 
%hash = ("小明"=>{'语文'=>50, '数学'=>60},
        "小刚"=>{'语文'=>80, '数学'=>90});
 
foreach my $key ( keys %hash )
{
    print "$key:\n";
    my $subhash = $hash{$key};
    foreach my $subkey ( keys %$subhash )
    {
        print "\t$subkey => $$subhash{$subkey}\n";
    }
}