为什么要在Perl中返回散列或散列引用？

完成以下最有效的方法是什么？ (我知道他们完成同样的事情,但是大多数人如何在三者之间做到这一点,为什么？)

文件a.pl

@H_124_4@my %hash = build_hash(); # Do stuff with hash using $hash{$key} sub build_hash { # Build some hash my %hash = (); my @k = qw(hi bi no th xc ul 8e r); for ( @k ) { $hash{$k} = 1; } # Does this return a copy of the hash?? return %hash; }

文件b.pl

@H_124_4@my $hashref = build_hash(); # Do stuff with hash using $hashref->{$key} sub build_hash { # Build some hash my %hash = (); my @k = qw(hi bi no th xc ul 8e r); for ( @k ) { $hash{$k} = 1; } # Just return a reference (smaller than making a copy?) return \%hash; }

文件c.pl

@H_124_4@my %hash = %{Build_hash()}; # Do stuff with hash using $hash{$key} # it is better,because now we don't have to dereference our hashref each time using ->? sub build_hash { # Build some hash my %hash = (); my @k = qw(hi bi no th xc ul 8e r); for ( @k ) { $hash{$k} = 1; } return \%hash; }