JS遍历Json字符串中键值对先转成JSON对象再遍历

1、将Json字符串转换成JSON对象

var t="{"firstName": "cyra", "lastName": "richardson"}"; var obj = eval（"（" + t + "）"）;

2、遍历读取键值对

for（var str in obj）{ alert（str+"="+obj[str]）; }