Javascript serialize : Variable handling : PHP functions in JavaScript JAVASCRIPT TUTORIALS

function serialize( mixed_value ) {
    // Returns a string representation of variable (which can later be unserialized)  
    // 
    // version: 812.3015
    // discuss at: http://phpjs.org/functions/serialize
    // +   original by: Arpad Ray (mailto:arpad@php.net)
    // +   improved by: Dino
    // +   bugfixed by: Andrej Pavlovic
    // +   bugfixed by: Garagoth
    // %          note: We feel the main purpose of this function should be to ease the transport of data between php & js
    // %          note: Aiming for PHP-compatibility, we have to translate objects to arrays
    // *     example 1: serialize(['Kevin', 'van', 'Zonneveld']);
    // *     returns 1: 'a:3:{i:0;s:5:"Kevin";i:1;s:3:"van";i:2;s:9:"Zonneveld";}'
    // *     example 2: serialize({firstName: 'Kevin', midName: 'van', surName: 'Zonneveld'});
    // *     returns 2: 'a:3:{s:9:"firstName";s:5:"Kevin";s:7:"midName";s:3:"van";s:7:"surName";s:9:"Zonneveld";}'
    var _getType = function( inp ) {
        var type = typeof inp, match;
        var key;
        if (type == 'object' && !inp) {
            return 'null';
        }
        if (type == "object") {
            if (!inp.constructor) {
                return 'object';
            }
            var cons = inp.constructor.toString();
            if (match = cons.match(/(\w+)\(/)) {
                cons = match[1].toLowerCase();
            }
            var types = ["boolean", "number", "string", "array"];
            for (key in types) {
                if (cons == types[key]) {
                    type = types[key];
                    break;
                }
            }
        }
        return type;
    };
    var type = _getType(mixed_value);
    var val, ktype = '';
    
    switch (type) {
        case "function": 
            val = ""; 
            break;
        case "undefined":
            val = "N";
            break;
        case "boolean":
            val = "b:" + (mixed_value ? "1" : "0");
            break;
        case "number":
            val = (Math.round(mixed_value) == mixed_value ? "i" : "d") + ":" + mixed_value;
            break;
        case "string":
            val = "s:" + mixed_value.length + ":\"" + mixed_value + "\"";
            break;
        case "array":
        case "object":
            val = "a";
            /*
            if (type == "object") {
                var objname = mixed_value.constructor.toString().match(/(\w+)\(\)/);
                if (objname == undefined) {
                    return;
                }
                objname[1] = serialize(objname[1]);
                val = "O" + objname[1].substring(1, objname[1].length - 1);
            }
            */
            var count = 0;
            var vals = "";
            var okey;
            var key;
            for (key in mixed_value) {
                ktype = _getType(mixed_value[key]);
                if (ktype == "function") { 
                    continue; 
                }
                
                okey = (key.match(/^[0-9]+$/) ? parseInt(key) : key);
                vals += serialize(okey) +
                        serialize(mixed_value[key]);
                count++;
            }
            val += ":" + count + ":{" + vals + "}";
            break;
    }
    if (type != "object" && type != "array") val += ";";
    return val;
}