如何按照添加到散列的顺序打印散列的键/值对.
例如：
%hash = ("a","1","b","2","c","3");
while (($key,$value) = each %hash) {
print "$key","$value\n";
}
以上结果如下：
c3 a1 b2
a1 b2 c3
提前致谢！
解决方法
由于您不想使用任何提到的模块(Tie :: IxHash和Tie :: Hash :: Indexed),并且由于哈希值为
unordered collections(如前所述),因此您必须在插入值时存储此信息：
#!/usr/bin/perl
use warnings;
use strict;
my %hash;
my %index; #keep track of the insertion order
my $i=0;
for (["a","1"],["b","2"],["c","3"]) { #caveat: you can't insert values in your hash as you did before in one line
$index{$_->[0]}=$i++;
$hash{$_->[0]}=$_->[1];
}
for (sort {$index{$a}<=>$index{$b}} keys %hash) { #caveat: you can't use while anymore since you need to sort
print "$_$hash{$_}\n";
}
这将打印：
a1 b2 c3