javascript获取未知对象属性以及属性值

var o = new Object();

 o.a="1111"

 o.b="2222"

 alert(o.a);

 alert(o.b);

 for(attribute in o){

  var attrName = attribute;

  alert(attrName);

  var value = null;

  eval("value=o."+attrName);

  alert(value);

 }