Error with json Uncaught TypeError: Cannot read property 'choices' of undefined

Question

choices is a nested array in json object i am placing this data for a multiple choice quiz sequence. When i press the trigger for the function the console says 'Uncaught TypeError: Cannot read property 'choices' of undefined' i also have a variable 'c' which changes when the user selects another exam so the the statement exam=exam+c would mat the placement function work.

var exam0 = [
    {
        "question": "which is a negative number?",
        "choices": [
            "2",
            "-2",``
            "6",
            "8",
        ],
        "correctAnswer": "B",
        "hint": "The one with the ' - ' negative sign"
    },
    ......other questions****
 
];

The function is

function placement(x) /*x is variable used to change the question from the json object*/
{
    choiceOne=$('<p>').text('A.'+exam[x].choices[0]); /*where the console points to problem*/
    choiceTwo=$('<p>').text('B.'+exam[x].choices[1]);
    choiceThree=$('<p>').text('C.'+exam[x].choices[2]);
    choiceFour=$('<p>').text('D.'+exam[x].choices[3]);
    currentQuestion=$('<p>').text(exam[x].question);
    $("#honeyPot").empty().append(currentQuestion);
    $("#honeyPot p").prepend(count+".");
    $('#options').find('p').remove().hide();
    $('#optionOne').fadeIn(250).append(choiceOne);
    $('#optionTwo').fadeIn(250).append(choiceTwo);      
    $('#optionThree').fadeIn(250).append(choiceThree);
    $('#optionFour').fadeIn(250).append(choiceFour);    
}

Answer 1

I think you should use exam0 in your function too instead of exam since exam0 is the json object.

function placement(x) /*x is variable used to change the question from the json object*/
{
    choiceOne=$('<p>').text('A.'+exam0[x].choices[0]); /*where the console points to problem*/
    choiceTwo=$('<p>').text('B.'+exam0[x].choices[1]);
    choiceThree=$('<p>').text('C.'+exam0[x].choices[2]);
    choiceFour=$('<p>').text('D.'+exam0[x].choices[3]);
    currentQuestion=$('<p>').text(exam0[x].question);
    $("#honeyPot").empty().append(currentQuestion);
    $("#honeyPot p").prepend(count+".");
    $('#options').find('p').remove().hide();
    $('#optionOne').fadeIn(250).append(choiceOne);
    $('#optionTwo').fadeIn(250).append(choiceTwo);      
    $('#optionThree').fadeIn(250).append(choiceThree);
    $('#optionFour').fadeIn(250).append(choiceFour);    
}