判斷HASH VALUE的未定義值出錯(cuò)（已解決）

jjqing

#!/usr/bin/perl
use strict;
use warnings;
use diagnostics;
use Smart::Comments '###';

my (%hash,$result);

%hash = (
    cluster_name => undef,
    column_name => 'OBJ#',
    column_position => '1',
    extents => '102',
    index_name => 'I_IDL_UB11',
    index_size => 2097152,
    index_tablespace_name => 'SYSTEM',
    index_type => 'NORMAL',
    iot_type => undef,
    nested => 'NO',
    owner => 'SYS',
    table_name => 'IDL_UB1$',
    table_size => 260046848,
    tablespace_name => 'SYSTEM',
    temporary => 'N'
);
### %hash
push ( @$result, { %hash } );
### $result

foreach my $a ( @{ $result } ) {
    my $hash;
    ### $a
    if ( defined $a->{cluster_name} ) { #此處為何老是報(bào)"Use of uninitialized value"
        $hash->{table_type} = 'CLUSTER';
    }
    elsif ( defined $a->{iot_type} ) {
        $hash->{table_type} = $a->{iot_type};
    }
    elsif ( $a->{nested} ne "NO" ) {
        $hash->{table_type} = '嵌套表';
    }
    elsif ( $a->{temporary} ne "N") {
        $hash->{table_type} = "臨時(shí)表";
    }
    elsif ( $a->{partitioned} eq "YES") {
        $hash->{table_type} = "分區(qū)表";
    }
    else {
        $hash->{table_type} = "堆表";
    }
}

=d 以下是運(yùn)行屏幕顯示
[teamsun@TeamWorks tmp]$ perl 8
### $a: {
###       cluster_name => undef,
###       column_name => 'OBJ#',
###       column_position => '1',
###       extents => '102',
###       index_name => 'I_IDL_UB11',
###       index_size => 2097152,
###       index_tablespace_name => 'SYSTEM',
###       index_type => 'NORMAL',
###       iot_type => undef,
###       nested => 'NO',
###       owner => 'SYS',
###       table_name => 'IDL_UB1$',
###       table_size => 260046848,
###       tablespace_name => 'SYSTEM',
###       temporary => 'N'
###     }
Use of uninitialized value in string eq at 1 line 35 (#1)
    (W uninitialized) An undefined value was used as if it were already
    defined.  It was interpreted as a "" or a 0, but maybe it was a mistake.
    To suppress this warning assign a defined value to your variables.
    To help you figure out what was undefined, perl tells you what operation
    you used the undefined value in.  Note, however, that perl optimizes your
    program and the operation displayed in the warning may not necessarily
    appear literally in your program.  For example, "that $foo" is
    usually optimized into "that " . $foo, and the warning will refer to
    the concatenation (.) operator, even though there is no . in your
    program.
=cut

請(qǐng)問(wèn)各位，為什么對(duì)這個(gè)HASH VALUE判斷老是出錯(cuò)呢？謝謝！

jjqing

很感謝，原來(lái)就是因?yàn)?hash里面沒(méi)有'partitioned‘這個(gè)KEY，所以才導(dǎo)致這段報(bào)錯(cuò)，現(xiàn)在已經(jīng)修改，使%hash包含了partition，運(yùn)行已經(jīng)不報(bào)錯(cuò)了。

謝謝！

jjqing

回復(fù) 2# q1208c

不好意思，%hash里面沒(méi)有partitioned這個(gè)KEY，所以測(cè)試腳本改成如下，我的PERL版本是：This is perl, v5.8.9 built for x86_64-linux

1. #!/usr/bin/perl
   
2. use strict;
   
3. use warnings;
   
4. use diagnostics;
   
5. use Smart::Comments '###';
   
6. 
   
7. my (%hash,$result);
   
8. 
   
9. %hash = (
   
10.     cluster_name => undef,
    
11.     column_name => 'OBJ#',
    
12.     column_position => '1',
    
13.     extents => '102',
    
14.     index_name => 'I_IDL_UB11',
    
15.     index_size => 2097152,
    
16.     index_tablespace_name => 'SYSTEM',
    
17.     index_type => 'NORMAL',
    
18.     iot_type => undef,
    
19.     nested => 'NO',
    
20.     owner => 'SYS',
    
21.     table_name => 'IDL_UB1,
    
22.     table_size => 260046848,
    
23.     tablespace_name => 'SYSTEM',
    
24.     temporary => 'N'
    
25. );
    
26. 
    
27. ### %hash
    
28. push ( @$result, { %hash } );
    
29. ### $result
    
30. 
    
31. 
    
32. foreach my $a ( @{ $result } ) {
    
33.     my $hash;
    
34.     ### $a
    
35.     if ( defined $a->{cluster_name} ) {
    
36.         $hash->{table_type} = 'CLUSTER';
    
37.     }
    
38.     elsif ( defined $a->{iot_type} ) {
    
39.         $hash->{table_type} = $a->{iot_type};
    
40.     }
    
41.     elsif ( $a->{nested} ne "NO" ) {
    
42.         $hash->{table_type} = '嵌套表';
    
43.     }
    
44.     elsif ( $a->{temporary} ne "N") {
    
45.         $hash->{table_type} = "臨時(shí)表";
    
46.     }
    
47.     else {
    
48.         $hash->{table_type} = "堆表";
    
49.     }
    
50. 
    
51. }
    

復(fù)制代碼

q1208c

1.    elsif ( $a->{partitioned} eq "YES") {
   
2.         $hash1->{table_type} = "分區(qū)表";
   

復(fù)制代碼

我這里是這段報(bào)錯(cuò).