Convert js Array() to JSon object for use with JQuery .ajax

Don’t make it an Array if it is not an Array, make it an object:

var saveData = {};
saveData.a = 2;
saveData.c = 1;

// equivalent to...
var saveData = {a: 2, c: 1}

// equivalent to....
var saveData = {};
saveData['a'] = 2;
saveData['c'] = 1;

Doing it the way you are doing it with Arrays is just taking advantage of Javascript’s treatment of Arrays and not really the right way of doing it.