声明数据结构 包含复杂数据结构

#下面有4个例子，但通常最后一个更常用。
my %owner1 = (
    "name" => "Santa Claus",
    "DOB" => "1882-12-25",
);

my $owner1Ref = %owner1;

my %owner2 = (
    "name" => "Mickey Mouse",
    "DOB" => "1928-11-18",
);

my $owner2Ref = %owner2;

my @owners = ( $owner1Ref, $owner2Ref );

my $ownersRef = @owners;

my %account = (
    "number" => "12345678",
    "opened" => "2000-01-01",
    "owners" => $ownersRef,
);

#显然你不用这么费劲，可以简化为：
my %owner1 = (
    "name" => "Santa Claus",
    "DOB" => "1882-12-25",
);

my %owner2 = (
    "name" => "Mickey Mouse",
    "DOB" => "1928-11-18",
);

my @owners = ( %owner1, %owner2 );

my %account = (
    "number" => "12345678",
    "opened" => "2000-01-01",
    "owners" => @owners,
);

#也可以使用不同的符号声明匿名数组和哈希表。匿名数组使用方括号，匿名哈希表使用大括号。 这样，返回值就是一个对匿名数据结构的引用。细看一下， 返回的 %accountas 与上面相同：
# Braces denote an anonymous hash
my $owner1Ref = {
    "name" => "Santa Claus",
    "DOB" => "1882-12-25",
};

my $owner2Ref = {
    "name" => "Mickey Mouse",
    "DOB" => "1928-11-18",
};

# Square brackets denote an anonymous array
my $ownersRef = [ $owner1Ref, $owner2Ref ];

my %account = (
    "number" => "12345678",
    "opened" => "2000-01-01",
    "owners" => $ownersRef,
);

#或者更短一些（这就是真正用来声明复杂数据结构的形式）：
my %account = (
    "number" => "31415926",
    "opened" => "3000-01-01",
    "owners" => [
        {
            "name" => "Philip Fry",
            "DOB" => "1974-08-06",
        },
        {
            "name" => "Hubert Farnsworth",
            "DOB" => "2841-04-09",
        },
    ],
);

say "$account{owners}[0]{ddddd}";
say "$account{owners}[1]{aaaa}";
say "$account{owners}->[0]->{ddddd}";
say "$account{owners}->[1]->{aaaa}";