Question

Ok, so here’s the entire structure I’m trying to create. I need to create an anonymous array that I can use as a hash value. This works in my program:

$result = {
    count, 2,
    elementList, [
        {name => "John Doe", age => 23},
        {name => "Jane Doe", age => 24}
    ]
};

I’m trying to create the exact same thing with code like this. This works:

my @elements = [
     {name => "John Doe", age => 23},
     {name => "Jane Doe", age => 24}
];

$result = {
    count, 2,
    elementList, @elements
};

But this does NOT work:

my @elements;
push(@elements, {name => "John Doe", age => 23});
push(@elements, {name => "Jane Doe", age => 24});

$result = {
    count, 2,
    elementList, @elements
};

Answer 1

As others have mentioned, you’re describing an unusual data structure: an array with only one element, which is an arrayref of hashrefs. I’ll assume that you really do want that structure for some reason.

my @elements = [
    {name => "John Doe", age => 23},
    {name => "Jane Doe", age => 24}
];

is equivalent to

my @elements = [];
push(@{ $elements[0] }, {name => "John Doe", age => 23});
push(@{ $elements[0] }, {name => "Jane Doe", age => 24});

because you want to push the hashrefs onto the arrayref in $elements[0], not the @elements array.

But it’s unusual to have an array with only one element. Looking at the additional code you’ve posted, what you really want is this:

my $elementsRef = [];
push(@$elementsRef, {name => "John Doe", age => 23});
push(@$elementsRef, {name => "Jane Doe", age => 24});

Or this:

my @elements;
push(@elements, {name => "John Doe", age => 23});
push(@elements, {name => "Jane Doe", age => 24});

and then use \@elements where you currently use @elements.

Either one of those will work. It’s up to you to decide which one you prefer. I’d probably go with the second version.