难道perl类只能存两个数组的数组,附代码,求解答

clyman

Bean.pm

package Bean; use strict; use Class::Struct; struct Bean => {   name => '$',   list => '@', }; 1;

test.pl

use strict; use Bean; my $bean; my @l; my @list; my @beans; @l = ('111', '112', '113'); push(@list, [@l]); @l = ('121', '122', '123'); push(@list, [@l]); @l = ('131', '132', '133'); push(@list, [@l]); @l = ('141', '142', '143'); push(@list, [@l]); $bean = Bean->new(); $bean->name("name1"); $bean->list(@list); push(@beans, $bean); @l = ('211', '212', '213'); push(@list, [@l]); @l = ('221', '222', '223'); push(@list, [@l]); @l = ('231', '232', '233'); push(@list, [@l]); @l = ('241', '242', '243'); push(@list, [@l]); $bean = Bean->new(); $bean->name("name2"); $bean->list(@list); push(@beans, $bean); @l = ('311', '312', '313'); push(@list, [@l]); @l = ('321', '322', '323'); push(@list, [@l]); @l = ('331', '332', '333'); push(@list, [@l]); @l = ('341', '342', '343'); push(@list, [@l]); $bean = Bean->new(); $bean->name("name3"); $bean->list(@list); push(@beans, $bean); @l = ('411', '412', '413'); push(@list, [@l]); @l = ('421', '422', '423'); push(@list, [@l]); @l = ('431', '432', '433'); push(@list, [@l]); @l = ('441', '442', '443'); push(@list, [@l]); $bean = Bean->new(); $bean->name("name4"); $bean->list(@list); push(@beans, $bean); foreach(@beans) {   my $name = $_->name();   my $list = $_->list();   print 'name is:' . $name . "\n";   foreach(@$list)   {     my $list = $_;     foreach(@$list)     {       my $str = $_;       print $str . "\n";     }   } }

报错信息是
Too many args to list at E:\online\oop\test3\test.pl line 20

clyman

如果控制scalar(@list)为两个就没问题,为什么呢?
我原来是写java的,对于perl这样的数据结构现在很迷惑.....

flw

太复杂了，搞个简单的，能说明问题的上来。

clyman

use strict; use Bean; my $bean; my @l; my @list; @l = ('111', '112', '113'); push(@list, [@l]); @l = ('121', '122', '123'); push(@list, [@l]); @l = ('131', '132', '133'); push(@list, [@l]); @l = ('141', '142', '143'); push(@list, [@l]); $bean = Bean->new(); $bean->name("name1"); $bean->list(@list); my $listtmp = $bean->list(); foreach(@$listtmp) {   my $listtmp2 = $_;   foreach(@$listtmp2)   {     my $str = $_;     print $str . "\n";   } }

clyman

您给分析分析

Nosferatu

Class::Struct里的文档说的很清楚：

Array ('@' or '*@')

    The element is an array, initialized by default to ().

    With no argument, the accessor returns a reference to the element's whole array (whether or not the element was specified as '@' or '*@').

    With one or two arguments, the first argument is an index specifying one element of the array; the second argument, if present, is assigned to the array element. If the element type is '@', the accessor returns the array element value. If the element type is '*@', a reference to the array element is returned.

    As a special case, when the accessor is called with an array reference as the sole argument, this causes an assignment of the whole array element. The object reference is returned.

royalzhang

$bean->list(@list);
是错误的，struct里面是hash，其value只能为标量，所以上面代码应该是：
$bean->list(\@list);

ulmer

Hi,
just like Nosferatu said, pls read more perldoc in details.
this is demo code  4u:

1. 
   
2. use Class::Struct;
   
3. 
   
4. struct Breed => {
   
5.     name  => '$',
   
6.     cross => '$',
   
7. };
   
8. 
   
9. struct Cat => [
   
10.     name     => '$',
    
11.     kittens  => '@',
    
12.     markings => '%',
    
13.     breed    => 'Breed',
    
14.    
    
15.    
    
16. ];
    
17. 
    
18. struct Bean => {
    
19.     list => '@',
    
20. };
    
21. 
    
22. # main
    
23. 
    
24. my $cat = Cat->new(
    
25.     name     => 'Socks',
    
26.     kittens  => ['Monica', 'Kenneth'],
    
27.     markings => { socks=>1, blaze=>"white" },
    
28.     breed    => Breed->new(name=>'short-hair', cross=>1),
    
29. );   
    
30. 
    
31. # Add more name in the list of kittens
    
32. push @{$cat->kittens},  ("miao", "mimi", "mini");
    
33. 
    
34. print "Once a cat called ", $cat->name, "\n";
    
35. print "(which was a ", $cat->breed->name, ")\n";
    
36. print "had " . scalar(@{$cat->kittens}) . " kittens: ", join(', ', @{$cat->kittens}), "\n";
    
37. 
    
38. #### your Bean for example:
    
39. my $obj = Bean->new();
    
40. my @arr1 = (1,2,3);
    
41. my @arr2 = (4,5,6);
    
42. push @{$obj->list}, @arr1; # don't use reference of array !!!
    
43. push @{$obj->list}, @arr2;
    
44. print "\$obj->list: ", join ", ", @{$obj->list}, "\n";
    
45. 
    

复制代码

Mery Christmas and Happy New year!

-- ulmer

clyman

谢谢各位,找到错误了

$bean->list(@list);
应该是
$bean->list([@list]);
就好了,^.^