数组的数组

Perl 免费提供许多数据结构，这些数据结构在其他编程语言里是需要你自己制作的。

比如那些计算机 科学的新芽们都需要学习的堆栈和队列在 Perl 里都只是数组

pop:
pop 操作将数组的最后一个元素取出并返回：



Vsftp:/root/perl/5# cat a1.pl 
my @arr=qw/a b c d e f g/;
print "@arr is @arr
";
pop @arr;
print "@arr is @arr
";

Vsftp:/root/perl/5# perl a1.pl 
@arr is a b c d e f g
@arr is a b c d e f

push，它可以将一个元素（或者一列元素）加在数组的末尾：

Vsftp:/root/perl/5# cat a1.pl 
my @arr=qw/a b c d e f g/;
print "@arr is @arr
";
pop @arr;
print "@arr is @arr
";

push (@arr,'xxyy');
print "@arr is @arr
";
Vsftp:/root/perl/5# perl a1.pl 
@arr is a b c d e f g
@arr is a b c d e f
@arr is a b c d e f xxyy

shift 拿掉数组最左边的一个值
Vsftp:/root/perl/5# cat a2.pl 
my @arr=qw/a b c d e f g/;
print "@arr is @arr
";
shift @arr;
print "@arr is @arr
";


Vsftp:/root/perl/5# perl a2.pl 
@arr is a b c d e f g
@arr is b c d e f g



unshift:添加一个值到数组的最左边。


Vsftp:/root/perl/5# cat a2.pl 
my @arr=qw/a b c d e f g/;
print "@arr is @arr
";
unshift (@arr,'999');
print "@arr is @arr
";

Vsftp:/root/perl/5# perl a2.pl 
@arr is a b c d e f g
@arr is 999 a b c d e f g



9.1 数组的数组

9.1.1 创建和访问一个两维数组


Vsftp:/root/perl/5# cat a3.pl 
@Aoa = (
["fred", "barney" ],
["george", "jane", "elroy" ],
["homer", "marge", "bart" ],
);

print @Aoa;
print "
";
Vsftp:/root/perl/5# perl a3.pl 
ARRAY(0xb55d48)ARRAY(0xb71358)ARRAY(0xb71538)


Vsftp:/root/perl/5# cat a3.pl 
@Aoa = (
["fred", "barney" ],
["george", "jane", "elroy" ],
["homer", "marge", "bart" ],
);

print @{$Aoa[0]};
print "
";
print $Aoa[0]->[1];
print "
";


Vsftp:/root/perl/5# perl a3.pl 
fredbarney
barney


# 创建一个指向一个数组的数组的引用。


Vsftp:/root/perl/5# cat a4.pl 
$ref_to_AoA = [
[ "fred", "barney", "pebbles", "bamm bamm", "dino", ],
[ "homer", "bart", "marge", "maggie", ],
[ "george", "jane", "elroy", "judy", ],
];

print $ref_to_AoA;
print "
";
print @{$ref_to_AoA};
print "
";
print $ref_to_AoA->[0]->[3];
print "
";
Vsftp:/root/perl/5# perl a4.pl 
ARRAY(0x104c638)
ARRAY(0x1029d48)ARRAY(0x10455e0)ARRAY(0x1045670)
bamm bamm


请记住在每一对相邻的花括弧或方括弧之间有一个隐含的 ->


9.1.2 自行生长

Vsftp:/root/perl/5# cat aa
1   4 7
a1 a4 a7
z1 a6 z9

Vsftp:/root/perl/5# cat a5.pl 
open (A,"aa");
while (<A>){
   chomp $_;
   my @tmp = split(/s+/,$_);
   push @AOA ,[@tmp];
   };
print @AOA;
print "
";
print $AOA[1]->[1];
print "
";

Vsftp:/root/perl/5# perl a5.pl 
ARRAY(0xc02d48)ARRAY(0xc1e340)ARRAY(0xc1e5e0)
a4



/*****************************

Vsftp:/root/perl/5# perl a6.pl 
Type of arg 1 to push must be array (not scalar dereference) at a6.pl line 6, near "];"
Execution of a6.pl aborted due to compilation errors.
Vsftp:/root/perl/5# cat a6.pl 
open (A,"aa");
my @ref_to_AOA=@AOA;
while (<A>){
   chomp $_;
   my @tmp = split(/s+/,$_);
   push $ref_to_AOA ,[@tmp];
   };
print @AOA;
print "
";
print $AOA[1]->[1];
print "
";

Vsftp:/root/perl/5# perl a6.pl 
Type of arg 1 to push must be array (not scalar dereference) at a6.pl line 6, near "];"
Execution of a6.pl aborted due to compilation errors.



Vsftp:/root/perl/5# cat a7.pl 
sub func() {
    my $a=shift;
    my $b=shift;
    return $a + $b;
   };


for $x (0..9){ # 对每一行...
  for $y (0..9) { # 对每一列...
  $AoA[$x][$y] = &func($x, $y); # ...设置调用
  }
};


print  @AoA;
print "
";
print @{$AoA[0]};
print "
";
print @{$AoA[1]};
print "
";
print @{$AoA[2]};
print "
";
Vsftp:/root/perl/5# perl a7.pl 
ARRAY(0x692358)ARRAY(0x69e290)ARRAY(0x69e3b0)ARRAY(0x69e4d0)ARRAY(0x69e5f0)ARRAY(0x69e710)ARRAY(0x69e830)ARRAY(0x69e950)ARRAY(0x69ea70)ARRAY(0x69eb90)
0123456789
12345678910
234567891011

这种方式的访问:
$AoA[$x][$y]

$AoA[$x]->[$y]


Vsftp:/root/perl/5# cat a8.pl 
my @AoA=(1,2,3,[a1,a2,a3]);
print $AoA[3][2];
print "
";
print $AoA[3]->[2];
print "
";
Vsftp:/root/perl/5# 
Vsftp:/root/perl/5# perl a8.pl 
a3
a3



Vsftp:/root/perl/5# cat a9.pl 
use Data::Dumper;
my $ref_to_AoA=[(1,f2,f3),(a1,a2,a3),(z1,z2,z3)];
print Dumper($ref_to_AoA);
print "
";
print $ref_to_AoA->[0]."
";
print $ref_to_AoA->[1]."
";
print $ref_to_AoA->[2]."
";
print $ref_to_AoA->[3]."
";
print $ref_to_AoA->[4]."
";
print $ref_to_AoA->[5]."
";
print $ref_to_AoA->[6]."
";

Vsftp:/root/perl/5# perl a9.pl 
$VAR1 = [
          1,
          'f2',
          'f3',
          'a1',
          'a2',
          'a3',
          'z1',
          'z2',
          'z3'
        ];

1
f2
f3
a1
a2
a3
z1



Vsftp:/root/perl/5# cat a10.pl 
use Data::Dumper;
my $ref_to_AoA=[[1,f2,f3],[a1,a2,a3],[z1,z2,z3]];
print Dumper($ref_to_AoA);
print "
";
print $ref_to_AoA->[0]."
";
print $ref_to_AoA->[1]."
";
print $ref_to_AoA->[2]."
";
print  $ref_to_AoA->[0]->[2]."
";
Vsftp:/root/perl/5# perl a10.pl 
$VAR1 = [
          [
            1,
            'f2',
            'f3'
          ],
          [
            'a1',
            'a2',
            'a3'
          ],
          [
            'z1',
            'z2',
            'z3'
          ]
        ];

ARRAY(0x1742d48)
ARRAY(0x1796628)
ARRAY(0x178aa00)
f3



/****************************
Vsftp:/root/perl/5# cat a11.pl 
use Data::Dumper;
my $ref_to_AoA=[[1,f2,f3],[a1,a2,a3],[z1,z2,z3],[z1,z2,dsd3],[z1,z2,zdas3],[z1,z2,zda3]];
print Dumper($ref_to_AoA);
print "
";
print  $ref_to_AoA->[0]->[2]."
";
print  $ref_to_AoA->[1]->[2]."
";
print  $ref_to_AoA->[2]->[2]."
";
print  $ref_to_AoA->[3]->[2]."
";
print  $ref_to_AoA->[4]->[2]."
";
print  $ref_to_AoA->[5]->[2]."
";
for $x (0..5) { # 对每一行...
$ref_to_AoA->[$x][2] = &func($x); # ...设置第四行
};
print  $ref_to_AoA->[0]->[2]."
";
print  $ref_to_AoA->[1]->[2]."
";
print  $ref_to_AoA->[2]->[2]."
";
print  $ref_to_AoA->[3]->[2]."
";
print  $ref_to_AoA->[4]->[2]."
";
print  $ref_to_AoA->[5]->[2]."
";
sub func() {
    my $a=shift;
    my $b=shift;
    return $a + $b;
   };

Vsftp:/root/perl/5# perl a11.pl 


f3
a3
z3
dsd3
zdas3
zda3
0
1
2
3
4
5


Vsftp:/root/perl/5# cat a12.pl 
use Data::Dumper;
my @AoA=([1,f2,f3],[a1,a2,a3],[z1,z2,z3],[z1,z2,dsd3],[z1,z2,zdas3],[z1,z2,zda3]);
print @{ $AoA[0] };
print "
";
push @{ $AoA[0] }, "wilma", "betty";

print @{ $AoA[0] };
print "
";
Vsftp:/root/perl/5# perl a12.pl 
1f2f3
1f2f3wilmabetty


因为给 push 的参数必须是一个真正的数组，而不只是一个指向 一个数组的引
用。因此，第一个参数绝对必须以 @ 字符开头。而跟在 @ 后面的东西则可以忽略一些。


9.1.3  访问的和打印

现在把数据结构打印出来,如果你只想要一个元素,下面的就足够了:

Vsftp:/root/perl/5# cat a13.pl 
my @AoA=(1,2,3,[a1,a2,a3,a4]);
print $AoA[3][2];
print "
";
Vsftp:/root/perl/5# perl a13.pl 
a3

Vsftp:/root/perl/5# cat a13.pl 
my @AoA=(1,2,3,[a1,a2,a3,a4]);
print @AoA;
print "
";
Vsftp:/root/perl/5# perl a13.pl 
123ARRAY(0x2161d48)


Vsftp:/root/perl/5# cat a13.pl 
my @AoA=([1],[2],[3],[a1,a2,a3,a4]);
print @AoA;
print "
";
for $row (@AoA) {
print "@$row
";
}
Vsftp:/root/perl/5# perl a13.pl 
ARRAY(0x144fd48)ARRAY(0x146b340)ARRAY(0x146b550)ARRAY(0x146b598)
1
2
3
a1 a2 a3 a4



Vsftp:/root/perl/5# cat a13.pl 
my @AoA=([1],[2],[3],[a1,a2,a3,a4]);
for $i (0..$#AoA) {
print "row $i is: @{$AoA[$i]}
";
}
Vsftp:/root/perl/5# vim a13.pl 
Vsftp:/root/perl/5# cat a13.pl 
my @AoA=([1],[2],[3],[a1,a2,a3,a4]);
for $i (0..$#AoA) {
print "row $i is: @{$AoA[$i]}
";
}
Vsftp:/root/perl/5# perl a13.pl 
row 0 is: 1
row 1 is: 2
row 2 is: 3
row 3 is: a1 a2 a3 a4


9.1.4 片段

取出片段:
Vsftp:/root/perl/5# cat a14.pl 
my @AoA=([1,2,3],['aA','ADS','DSD'],['DAD',323,233],[232,'FF','344G'],['sas21','121','sad1231','asda1231','3131','sad213','adda','ewds']);
print @AoA;
print "
";
print $AoA[4]->[2];
print "
";

@part = ();
for ($y =3 ; $y < 8; $y++) {
push @part, $AoA[4][$y];
}
print @part;
print "
";


Vsftp:/root/perl/5# perl a14.pl 
ARRAY(0x900d48)ARRAY(0x927638)ARRAY(0x9276b0)ARRAY(0x927728)ARRAY(0x9277a0)
sad1231
asda12313131sad213addaewds
Vsftp:/root/perl/5# 



9.1.5  常见错误:

Vsftp:/root/perl/5# perl a16.pl 
ARRAY(0x1933d48) ARRAY(0x194f358) ARRAY(0x194f538)
Vsftp:/root/perl/5# cat a16.pl 
@AoA = ([2, 3], [4, 5, 7], [0] );
print "@AoA";
print "
";

Vsftp:/root/perl/5# perl a16.pl 
ARRAY(0x9f4d48) ARRAY(0xa10358) ARRAY(0xa10538)



Vsftp:/root/perl/5# cat a17.pl 
sub somefunc() {
     my $a=shift;
     return $a=3;
};

for $i (1..10) {
@array = &somefunc($i);
$AoA[$i] = [@array]; # 把数组引用给到对应的数组元素
};
print @AoA;
print "
";
Vsftp:/root/perl/5# perl a17.pl 
ARRAY(0x2547f40)ARRAY(0x2563358)ARRAY(0x2563628)ARRAY(0x2563670)ARRAY(0x25636b8)ARRAY(0x256c038)ARRAY(0x256c080)ARRAY(0x256c0c8)ARRAY(0x256c110)ARRAY(0x256c158)