perl中的范圍聲明our-my-local介紹

our $PROGRAM_NAME = "waiter";
{
my  $PROGRAM_NAME = "something";
our $PROGRAM_NAME = "server"; #這里的our和外面的相同，和前句不同。
# 這里調(diào)用的代碼看到的是"server"
}
# 這里執(zhí)行的代碼看到的仍然是"server".

sub greeting1{
    my ($hello) = "How are you do?";
    greeting2();
}
 
sub greeting2{
    print "$hello\n";
}
$hello = "How are you doing?";
greeting2();
greeting1();
greeting2();

How are you doing?
How are you doing?
How are you doing?

sub greeting1{
    local ($hello) = "How are you do?";
    greeting2();
}

sub greeting2{
    print "$hello\n";
}
$hello = "How are you doing?";
greeting2();
greeting1();
greeting2();

How are you doing?
How are you do?
How are you doing?