javascript解析JSON---将字符串转换为json对象

<script type="text/javascript">  
    var str = '{"name":"jack","age":21,"address":"shenzhen"}';  
    var jsonObject = eval('('+str+')');  
    alert("name="+jsonObject.name+",age="+jsonObject.age+",addess="+jsonObject.address);
 
</script>