provides utilities for dealing with query strings.

querystring.js

(function(exports) {
    var defaults = {
        sep: '&',
        eq: '=',
        // 把querystring中的值仅按字符串解析
        // 值为true时，如arr=[1,2] －> {"arr": "[1,2]"}
        beString: false
    };
    var querystring = {
        // 'str="aaa"&bool&num=123&arr=[1,2]&obj={"foo":1}'
        // -> { "str": "aaa", bool: true, num: 123, arr: [1, 2], obj: {"foo": 1} }
        parse: function(str, options) {
            if (typeof str !== 'string') {
                return {};
            }
            str = str.replace(/^\s+|\s+$/, '');
            if (str === '') {
                return {};
            }
            if (options === true) {
                options = {
                    beString: true
                };
            }
            options = options || {};
            var obj = {},
                pairs = str.split(options.sep || defaults.sep),
                pair = '',
                parts = [],
                key, val;

            while ((pair = pairs.shift())) {
                parts = pair.split(options.eq || defaults.eq);
                key = parts[0];
                val = parts[1];
                if (val) {
                    val = decodeURIComponent(val.replace(/\+/g, ' '));
                    val = (!options.beString && JSON.parse) ? JSON.parse(val) : val;
                } else {
                    val = true;
                }

                obj[key] = val;
            }

            return obj;
        },
        // { "str": "aaa", bool: true, num: 123, arr: [1, 2], obj: {"foo": 1} }
        // -> "str=%22aaa%22&bool=true&num=123&arr=%5B1%2C2%5D&obj=%7B%22foo%22%3A1%7D"
        stringify: function(obj, options) {
            if (!obj) {
                return '';
            }
            if (options === true) {
                options = {
                    beString: true
                };
            }
            options = options || {};
            var pairs = [],
                key = '',
                val = '';
            for (var k in obj) {
                if (obj.hasOwnProperty(k)) {
                    key = encodeURIComponent(k);
                    val = (!options.beString && JSON.stringify) ? JSON.stringify(obj[k]) : obj[k];
                    val = encodeURIComponent(val);
                    pairs.push(key + (options.eq || defaults.eq) + val);
                }
            }
            return pairs.join(options.sep || defaults.sep);
        }
    };

    exports.querystring = querystring;
})(this);