perl 师姐的秘籍

#1 遍历二维哈希+宇宙飞船符

foreach my $key1 (keys %hash){

  my $hash2 = $hash{$key1};

  foreach my $key2 (sort{$hash2->{$b}<=>$hash2->{$a}} keys %$hash2){

    print $key1.”\t”.$key2.”\t”.$hash2->{$key2}.”\n”;

  }

}

#2 控制输出小数点位数

my $var=123.454789;

$var=sprintf "%.2f",$var;

print $var."\n";

#3 子函数传参

my @alt_deps=split(/\,/,$_[0]);