jQuery multidimensional array definition

You Need to initialize the object first. Just write

questions = [];
for (var i = 0; i < tmp_questions.length; i++) {
    questions[i] = {};
    questions[i]["questions"] = tmp_questions[i];
    questions[i]["input_type_id"] = tmp_question_types[i];
    questions[i]["choices"] = tmp_choices[i];
}

You have to initialize before inserting. Check this

var tmp_choices= tmp_question_types = tmp_questions = [1,2,3,4,5];

var questions = [];  // If you want questions to be array of objects then use []

for (var i = 0; i < tmp_questions.length; i++) {
questions[i] = {};
    questions[i]["questions"] = tmp_questions[i];
    questions[i]["input_type_id"] = tmp_question_types[i];
    questions[i]["choices"] = tmp_choices[i];
}
console.log(questions);

You have to create your object into your array before pushing data into it :

    var questions = []; // here is an array
    for (var i = 0; i < tmp_questions.length; i++) {
        questions[i] = {}; // here is an empty object
        questions[i]["questions"] = tmp_questions[i];
        questions[i]["input_type_id"] = tmp_question_types[i];
        questions[i]["choices"] = tmp_choices[i];
    }

actually you could do :

var questions = [];
for(...){
    questions[i] = {
        questions : tmp_questions[i],
        "input_type_id" : tmp_question_types[i],
        choices :  tmp_choices[i]
    }
}

Hope that help, Paul J

You are almost there with several corrections.

Error 1 :

var questions = {}; 

That is an object declaration. Not array.

Error 2 :

questions[i]["questions"]

To do that you must have an object at position i of questions.

So after corrections,

var questions = [];  //declare arry
for (var i = 0; i < tmp_questions.length; i++) {
    questions.push({}); //push it
    questions[i]["questions"] = tmp_questions[i]; // add properties
    questions[i]["input_type_id"] = tmp_question_types[i];
    questions[i]["choices"] = tmp_choices[i];

}

Your array is not a Multi-dimensional Array, but just an array of objects. A multidimensional array should be one like:

var bidimensionalArray = new Array(new Array());
var tridimensionalName = new Array(new Array(new Array()));

Anyway, in order to create an array that could contains an object with: "questions, ids and choices", you have to initialize every element of the array.

See following please:

var tmp_questions = ["test1", "test2"];
var tmp_question_types = ["type1", "type2"];
var tmp_choices = ["choice1", "choice2"];


var questions = new Array(); 
for (var i = 0; i < tmp_questions.length; i++) {
    questions[i] = {};
    questions[i]["questions"] = tmp_questions[i];
    questions[i]["input_type_id"] = tmp_question_types[i];
    questions[i]["choices"] = tmp_choices[i];
}

console.log(questions);

I hope it helps you, bye.