但是HASH的键则全部必须是唯一的字符窜

访问hash元素
[oracle@jhoa 9]$ cat 4.pl 
my %hash = ("a" => 1,"b" => 2,"c" => 3);
$var= $hash{a};
print "\$var is $var\n";

[oracle@jhoa 9]$ perl 4.pl 
$var is 1


hash 键赋值


[oracle@jhoa 9]$ cat 5.pl 
my %hash = ("a" => 1,"c" => 3);
foreach $var (qw/a b c/){
print "I've head of $var $hash{$var}.\n";
}
[oracle@jhoa 9]$ perl 5.pl 
I've head of a 1.
I've head of b 2.
I've head of c 3.