[javascript] JSON.stringify doesn't work with normal Javascript array

I must be missing something here, but the following code (Fiddle) returns an empty string:

var test = new Array();
test['a'] = 'test';
test['b'] = 'test b';
var json = JSON.stringify(test);
alert(json);

What is the correct way of JSON'ing this array?

Nice explanation and example above. I found this (JSON.stringify() array bizarreness with Prototype.js) to complete the answer. Some sites implements its own toJSON with JSONFilters, so delete it.

if(window.Prototype) {
    delete Object.prototype.toJSON;
    delete Array.prototype.toJSON;
    delete Hash.prototype.toJSON;
    delete String.prototype.toJSON;
}

it works fine and the output of the test:

console.log(json);

Result:

"{"a":"test","b":["item","item2","item3"]}"

Alternatively you can use like this

var test = new Array();
test[0]={};
test[0]['a'] = 'test';
test[1]={};
test[1]['b'] = 'test b';
var json = JSON.stringify(test);
alert(json);

Like this you JSON-ing a array.

I posted a fix for this here

You can use this function to modify JSON.stringify to encode arrays, just post it near the beginning of your script (check the link above for more detail):

// Upgrade for JSON.stringify, updated to allow arrays
(function(){
    // Convert array to object
    var convArrToObj = function(array){
        var thisEleObj = new Object();
        if(typeof array == "object"){
            for(var i in array){
                var thisEle = convArrToObj(array[i]);
                thisEleObj[i] = thisEle;
            }
        }else {
            thisEleObj = array;
        }
        return thisEleObj;
    };
    var oldJSONStringify = JSON.stringify;
    JSON.stringify = function(input){
        if(oldJSONStringify(input) == '[]')
            return oldJSONStringify(convArrToObj(input));
        else
            return oldJSONStringify(input);
    };
})();

Json has to have key-value pairs. Tho you can still have an array as the value part. Thus add a "key" of your chousing:

var json = JSON.stringify({whatver: test});