document.write('<div>解析：</div><div>标准方法：</div><div>if(object.prototype.toString.call(a) == \'[object Array]\'){</div><div>&nbsp;// 是数组对象</div><div>}</div><div>常用方法：</div><div>if(a.constructor == Array){</div><div>&nbsp;// 是数组对象；</div><p>}&nbsp;</p>');