function parseParam(param, key) {
  var paramStr = "";
  if (param instanceof String || param instanceof Number || param instanceof Boolean
  ) {
    paramStr += "&" + key + "=" + encodeURIComponent(param);
  }
  else {
    $.each(param, function (i, p) {
      if (p == null || p == undefined)
        return true;
      var k = key == null ? i : key + (param instanceof Array ? "[" + i + "]" : "." + i);
      paramStr += '&' + parseParam(this, k);
    });
  }
  return paramStr.substr(1);
};

//调用：
var obj={name:'tom','class':{className:'class1'},classMates:[{name:'lily'}]};
parseParam(obj);
//结果：
"name=tom&class.className=class1&classMates[0].name=lily"
parseParam(obj,'stu');
//结果：
"stu.name=tom&stu.class.className=class1&stu.classMates[0].name=lily"