多个哈希按value降序排序时，能否 只用1个子程序

weichanghe2000

大家好，请教1个问题：
多个哈希按value降序排序时，能否 只用1个子程序，而不用2个呢（如果有5个或者6个哈希时，代码变得冗余）？
比如有2个哈希，按value降序排序时，可以用下面的代码实现：

1. my (%courses, %courses1);
   
2. sub desc_sort_subject {
   
3. $courses{$b} <=> $courses{$a}; # Numeric sort descending
   
4. }
   
5. sub desc_sort_subject_1 {
   
6. $courses1{$b} <=> $courses1{$a}; # Numeric sort descending
   
7. }
   
8. 
   
9. %courses = (
   
10. "Portland Panthers" => 10,
    
11. "Sunnyvale Sluggers" => 12,
    
12. "Chico Wildcats" => 5,
    
13. "Stevensville Tigers" => 6,
    
14. "Lewiston Blazers" => 11,
    
15. "Danville Terriors" => 8,
    
16. );
    
17. %courses1 = (
    
18. "Portland Panthers" => 101,
    
19. "Sunnyvale Sluggers" => 121,
    
20. "Chico Wildcats" => 51,
    
21. "Stevensville Tigers" => 61,
    
22. "Lewiston Blazers" => 111,
    
23. "Danville Terriors" => 81,
    
24. );
    
25. 
    
26. 
    
27. foreach my $key (sort desc_sort_subject keys %courses  ) {
    
28. printf "\t%s%5d\n", $key, $courses{"$key"};
    
29. }
    
30. 
    
31. foreach my $key (sort desc_sort_subject_1 keys %courses1  ) {
    
32. printf "\t%s%5d\n", $key, $courses1{"$key"};
    
33. }
    

复制代码

sunzhiguolu

回复 1# weichanghe2000

   
    our %hCourses;
    my (%courses, %courses1);
    sub desc_sort_subject {
    $hCourses{$b} <=> $hCourses{$a}; # Numeric sort descending
    }
   

    %courses = (
    "Portland Panthers" => 10,
    "Sunnyvale Sluggers" => 12,
    "Chico Wildcats" => 5,
    "Stevensville Tigers" => 6,
    "Lewiston Blazers" => 11,
    "Danville Terriors" => 8,
    );
    %courses1 = (
    "Portland Panthers" => 101,
    "Sunnyvale Sluggers" => 121,
    "Chico Wildcats" => 51,
    "Stevensville Tigers" => 61,
    "Lewiston Blazers" => 111,
    "Danville Terriors" => 81,
    );


    foreach my $key (sort desc_sort_subject keys {%hCourses = %courses}  ) {
    printf "\t%s%5d\n", $key, $hCourses{"$key"};
    }

    foreach my $key (sort desc_sort_subject keys {%hCourses = %courses1}  ) {
    printf "\t%s%5d\n", $key, $hCourses{"$key"};
    }

   

weichanghe2000

回复 2# sunzhiguolu


你好，非常感谢回复。

我试了下，在window上面，我安装了perl5.14，可以正确执行。
但是我在linux：redhat5.8 系统自带的perl5.8.8里面执行会报错。

可以帮忙改成能够在 perl5.8.8 里面也正确吗？
多谢。

sunzhiguolu

回复 3# weichanghe2000
把错误信息贴出来, 或者弄个图片瞧瞧...
你上传的图片都出问题了, 没法看!

   

weichanghe2000

回复 4# sunzhiguolu

好的，我这边刷新后，可以正常看到图片。

1. Type of arg 1 to keys must be hash (not anonymous hash ({})) at 3.pl line 27, near "}  ) "
   
2. Type of arg 1 to keys must be hash (not anonymous hash ({})) at 3.pl line 31, near "}  ) "
   
3. Execution of 3.pl aborted due to compilation errors.
   

复制代码

1. This is perl, v5.8.8 built for i386-linux-thread-multi
   
2. 
   
3. Copyright 1987-2006, Larry Wall

复制代码

sunzhiguolu

回复 3# weichanghe2000
别费事了, 这样试下:

%hCourses = %courses;
foreach my $key (sort desc_sort_subject keys %hCourses  ) {
    printf "\t%s%5d\n", $key, $hCourses{"$key"};
    }

   

weichanghe2000

回复 6# sunzhiguolu


多谢，这样真的可以。
在redhat5.8的perl5.8.8里面按照value降序排序了，而且不报错。

再次感谢您的帮助。

jason680

回复 1# weichanghe2000

Would you like this way ...

sub sort_by_subject_desc(+) {
  my ($rhCour) = @_;
  return sort {$rhCour->{$b} <=> $rhCour->{$a}} keys %{$rhCour};
}


foreach my $key (sort_by_subject_desc(%courses)) {
  printf "\t%s%5d\n", $key, $courses{"$key"};
}

foreach my $key (sort_by_subject_desc(%courses1)) {
  printf "\t%s%5d\n", $key, $courses1{"$key"};
}

   

sunzhiguolu

回复 7# weichanghe2000
使用 Jason680 大神提供的方法吧.

   

weichanghe2000

回复 8# jason680

非常感谢。
但是 sub sort_by_subject_desc(+) {

(+)  这里面的 + 号是什么意思哦？没有见过这样的用法。

请帮忙解答下哈。
多谢。