Stringing JSON for stupid browsers

stringifyJSON.js

function stringifyJSON(obj) {
	var keyValuePair = [];

	switch(Object.prototype.toString.call(obj)) {
		case '[object Object]':
			for(var i in obj) {
				if(obj.hasOwnProperty(i)) {
					keyValuePair.push('"' + i + '":' + stringifyJSON(obj[i]));
				}
			}
			return '{' + keyValuePair.join(',') + '}';

		case '[object Array]':
			for(var i = 0, len = obj.length; i < len; ++i) {
				keyValuePair.push(stringifyJSON(obj[i]));
			}
			return '[' + keyValuePair.join(',') + ']';

		case '[object String]':
			return '"' + obj.toString() + '"';

		default:
			return '' + obj;
	}
}


// test case
var testCase = {
	num: 1234,
	obj: {
		num: 1224,
		arr: [1,2,3,4,5],
		mixarr: [1, '2', "3"]
	},
	arr: [{a:1}, {b:2}, true, false],
	bool: true
};

var standare = JSON.stringify(testCase);
var output = stringifyJSON(testCase);

console.log(standare);
console.log(output);
console.log(standare === output);


console.time('JSON.stringify');
for(var i = 0; i < 0xfffff; ++i)
	JSON.stringify(testCase);
console.timeEnd('JSON.stringify');


console.time('stringifyJSON');
for(var i = 0; i < 0xfffff; ++i)
	stringifyJSON(testCase);
console.timeEnd('stringifyJSON');