Store session as associative array

Question

Is there a way to store SESSION name as associative array?

I have this session below, that being set via ajax once radio button is click.

$question = span name wherein question is displaying 
$answer = radio button value
$_SESSION['$question'] = "answer";

Then I want to convert it into below, I want to retain session variable name as key.

$QandA = array (question1 => asnwer1, question2 => asnwer2, question3 => asnwer3 );

If I do like this and do vardump , it is becoming indexed array

$QandA = array ($_SESSION['$question']);

Not sure what to put as key.

  $QandA = array ("what should be here to get session variable name as key"  => $_SESSION['$question']);

Answer 1

Yes, there is. But I recommend you to use it like this. Every question is an array, what has a question and answer key.

$_SESSION['question1'] = array(
    'question' => 'The question',
    'answer1' => "the answer"
    'answer2' => "other answer",
    'answer3' => "more answer",
);
$_SESSION['question2'] = array(
    'question' => 'Another question',
    'answer1' => "Answer for the other question."
);

//First question
echo $_SESSION["question1"]['question'];
//Answers for the question
echo $_SESSION["question1"]['answer1'];
echo $_SESSION["question1"]['answer2'];
echo $_SESSION["question1"]['answer3'];

//Second question
echo $_SESSION["question2"]['question'];
//Answer for second question
echo $_SESSION["question2"]['answer1'];

Answer 2

Why not just store all the answers as an associated array within a single session key?

$_SESSION['question_answers'] = array(
    $question1 => $answer1,
    $question2 => $answer2,
    // etc etc    
);

You could then just add to it with every separate request, if necessary

$_SESSION['question_answers'][$question3] = $answer3;

And so on and so forth.