比方說,我有一個像下面這樣的hashref常數:如何取消引用hashref常量?
use constant DOGS => {
Lassie => 'collie',
Benji => 'mutt',
Scooby => 'great dane',
Goofy => '???'
};
我怎樣才能取消對它的引用正確獲取說..他們鍵出來的嗎?
warn ref DOGS; # HASH at untitled line 12.
warn keys(%{DOGS}); # Warning: something's wrong (empty list)
warn keys(DOGS); # Type of arg 1 to keys must be hash (not constant item)
以下是我似乎使它工作的唯一辦法:我在做什麼錯
my $dogs = DOGS;
warn keys(%$dogs); # LassieBenjiGoofyScooby at untitled line 15.
?
有幾種方法可以在Perl中定義常量,每個方法都有不同的好壞點。在這種情況下你用常量解決什麼問題? – 2010-04-16 21:31:15