perl 引用/hash

1?

#!/opt/exp/bin/perl -w
#array init
@a=();
@LoL=();

sub function {
        $j=@_;
        @a=("1","2","3");
        print "j=$jn";
        return @a; 
}
for $i (1..10) {
        @list = function ($i);
        #below two is the same,it is array reference
        $LoL[$i] = @list;
# it is the same with above code
#       $LoL[$i] = [ @list ];
# it is array number
       $LoL[$i] = scalar @list;
        #notes add {},reback to array
        print "2:@{$LoL[$i]} n";
        #print "2:$LoL[$i] n";
}

2:

#!/opt/exp/bin/perl -w
sub printSorted {
·#parameter1 is reference for array,parameter2 is hash.@_ list assign
        my ($data,%options) = @_;
        # get the value for array 
        print "$data->[3]n";
#get hash value
        print "$options{type}n";
}
#$list={"1","3","4"};
@list=("1","4");
printSorted (@list,dir => 'asc',type => 'numerical');

3

#!/opt/exp/bin/perl -w
my @array1 = (10,20,30,40,50); 
my @array2 = ( 1,2,@array1,3,4);
%hash=(abc=>123,def=>456); 
#reference to hash
$ref=%hash; 
#point to hash
print "%$refn"; 
print "$$ref{abc}n";

<span style="font-size:14px;">#!/opt/exp/bin/perl -w
#it doesn't use $_ in hash and array
#array
#set value
@list = (4,1,0);
foreach $item (@list) {
        printf ("%d->$itemn",$i++)
}
#hash
while (my ($key,$value) = each (%ENV)) {
        print "$key - $valuen";
}
my @val =sort keys %ENV;
for ($i=0;$i<@val;$i++) {
        $key=$val[$i];
        print "$key-----$ENV{$key} n";
}</span>

==
在将hash的keys? sort 后，sort是一个独立的循环操作.先这个函数。
map是一个独立的循环，输出key和value，
即按比较顺序输出key-value

print map {"$_ -> $hash{$_}"} sort {$a cmp $b} keys %hash;? 应该是print if aa ; 这种单句处理 上面的sort是一个执行