原生实现jquery param序列化参数

var
    rbracket = /\[\]$/,
    rCRLF = /\r?\n/g,
    op = Object.prototype,
    ap = Array.prototype,
    aeach = ap.forEach,
    ostring = op.toString;

function isFunction(it) {
    return ostring.call(it) === '[object Function]';
}

function isArray(it) {
    return ostring.call(it) === '[object Array]';
}

function isObject(it) {
    return ostring.call(it) === '[object Object]';
}

function buildParams(prefix, obj, traditional, add) {
    var name;

    if (isArray(obj)) {

        // Serialize array item.
        aeach.call(obj, function(v, i) {
            if (traditional || rbracket.test(prefix)) {

                // Treat each array item as a scalar.
                add(prefix, v);

            } else {

                // Item is non-scalar (array or object), encode its numeric index.
                buildParams(
                    prefix + '[' + (typeof v === 'object' && v != null ? i : '') + ']',
                    v,
                    traditional,
                    add,
                );
            }
        });

    } else if (!traditional && isObject(obj)) {

        // Serialize object item.
        for (name in obj) {
            buildParams(prefix + '[' + name + ']', obj[name], traditional, add);
        }

    } else {

        // Serialize scalar item.
        add(prefix, obj);
    }
}

// Serialize an array of form elements or a set of
// key/values into a query string
function jollyparam(a, traditional) {
    var prefix,
        s = [],
        add = function(key, valueOrFunction) {

            // If value is a function, invoke it and use its return value
            var value = isFunction(valueOrFunction) ? valueOrFunction() : valueOrFunction;

            s[s.length] = encodeURIComponent(key) + '=' +
                encodeURIComponent(value == null ? '' : value);
        };

    // If an array was passed in, assume that it is an array of form elements.
    if (isArray(a)) {

        // Serialize the form elements
        aeach.call(a, function(item) {
            add(item.name, item.value);
        });

    } else {

        // If traditional, encode the "old" way (the way 1.3.2 or older
        // did it), otherwise encode params recursively.
        for (prefix in a) {
            buildParams(prefix, a[prefix], traditional, add);
        }
    }

    // Return the resulting serialization
    return s.join('&');
};