javascript原生态遍历json对象数据

1. [代码][JavaScript]代码    

//设置一个json字符串变量并赋值
var jsonstr = '{"employees":[' +
'{"firstName":"Bill","lastName":"Gates" },' +
'{"firstName":"George","lastName":"Bush" },' +
'{"firstName":"Thomas","lastName":"Carter" }],"sdf":"sdf","山东":"济南","北京":"故宫"}';
//设置json字符串转化为json对象
var jsonobj = eval("("+jsonstr+")");
//循环遍历json对象所有数据
for(var p in jsonobj)//第一层循环
{
	if(typeof(jsonobj[p])=="object"){//如果json值还是一个object，则继续第二层循环
		var jsonobj2 = jsonobj[p];
		for(var k in jsonobj2){
			alert("firstname:"+k+jsonobj2[k].firstName);
			alert("lastName:"+k+jsonobj2[k].lastName);
		}
	}else{//如果是是字符串不是对象则直接输出
		alert(jsonobj[p]);
	}
}