First, I think you're calling it the wrong thing. JSON stands for JavaScript Object Notation - it's just a specification for representing some data in a string that explicitly mimics JavaScript object (and array, string, number and boolean) literals. You're trying to build up a JavaScript object dynamically - so the word you're looking for is object.

With that pedantry out of the way, I think that you're asking how to set object and array properties.

// make an empty object

var myObject = {};



// set the list1 property to an array of strings

myObject.list1 = ['1', '2'];



// you can also access properties by string

myObject['list2'] = [];

// accessing arrays is the same, but the keys are numbers

myObject.list2[0] = 'a';

myObject['list2'][1] = 'b';



myObject.list3 = [];

// instead of placing properties at specific indices, you

// can push them on to the end

myObject.list3.push({});

// or unshift them on to the beginning

myObject.list3.unshift({});

myObject.list3[0]['key1'] = 'value1';

myObject.list3[1]['key2'] = 'value2';



myObject.not_a_list = '11';

That code will build up the object that you specified in your question (except that I call it myObject instead of myJSON). For more information on accessing properties, I recommend the Mozilla JavaScript Guide and the book JavaScript: The Good Parts.