印迹~~~~

foreach my $key ( sort { $hash{$a} cmp $hash{$b} } keys %hash ) {

# do something with ($key, $value)

}

如果是按数字小到大排列，则代码如下：

foreach my $key ( sort { $hash{$a} <=> $hash{$b} } keys %hash ) {

     my $value = $hash{$key};

     #do something with ($key, $value)

}

全部介绍参考：https://blog.csdn.net/bruce_wang_janet/article/details/18925763