[摘要]与数组类似，通过引用访问哈希表的元素形式为$$pointer{$index}，当然，$index是哈希表的键值，而不仅是数字。还有几种访问形式，此外，构建哈希表还可以用=>操作符，可读性更好些。下面再看一个例子：1 #!/usr/bin/perl2 #3 # Using Array refe...
与数组类似，通过引用访问哈希表的元素形式为$$pointer{$index}，当然，$index是哈希表的键值，而不仅是数字。还有几种访问形式，此外，构建哈希表还可以用=>操作符，可读性更好些。下面再看一个例子：
1 #!/usr/bin/perl
2 #
3 # Using Array references
4 #
5 %weekday = (
6 '01' => 'Mon',
7 '02' => 'Tue',
8 '03' => 'Wed',
9 '04' => 'Thu',
10 '05' => 'Fri',
11 '06' => 'Sat',
12 '07' => 'Sun',
13 );
14 $pointer = \%weekday;
15 $i = '05';
16 printf "\n ================== start test ================= \n";
17 #
18 # These next two lines should show an output
19 #
20 printf '$$pointer{$i} is ';
21 printf "$$pointer{$i} \n";
22 printf '${$pointer}{$i} is ';
23 printf "${$pointer}{$i} \n";
24 printf '$pointer->{$i} is ';
25
26 printf "$pointer->{$i}\n";
27 #
28 # These next two lines should not show anything 29 #
30 printf '${$pointer{$i}} is ';
31 printf "${$pointer{$i}} \n";
32 printf '${$pointer->{$i}} is ';
33 printf "${$pointer->{$i}}";
34 printf "\n ================== end of test ================= \n";
35
结果输出如下：
================== start test =================
$$pointer{$i} is Fri
${$pointer}{$i} is Fri
$pointer->{$i} is Fri
${$pointer{$i}} is
${$pointer->{$i}} is
================== end of test =================
可以看到，前三种形式的输出显示了预期的结果，而后两种则没有。当你不清楚是否正确时，就输出结果看看。在Perl中，有不明确的代码就用print语句输出来实验一下，这能使你清楚Perl是怎样解释你的代码的。
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