Jquery form表单元素转为JSON字符串

function formToJson(formObj){
    var o = {};
    var a = formObj.serializeArray();
    $.each(a, function() {

        if(this.value){
            if (o[this.name]) {
                if (!o[this.name].push) {
                    o[this.name] = [ o[this.name] ];
                }
                    o[this.name].push(this.value || null);
            } else {
                if($("[name='"+this.name+"']:checkbox",formObj).length){
                    o[this.name]=[this.value];
                }else{
                    o[this.name] = this.value || null;
                }
            }
        }
    });
    alert(JSON.stringify(o));
    return o;
};