javascript中json对象与字符串互转及取值

一、   json字符串转换为javascript对象，并取值

var answer = '{"id":0}'
var value= JSON.parse(answer);    //转换为json对象
alert(value.id);                  //取值

二、javascript对象转换为json字符串

沿用例子中value

var json_str= JSON.stringify(value);     //转换为json字符串　　

三、json数组字符串转换为json对象，并取值

var jsonStr = '[
{"id":"01","open":false,"pId":"1","name":"A部门"},
{"id":"02","open":false,"pId":"2","name":"B部门"},
{"id":"03","open":false,"pId":"3","name":"B部门"},   
{"id":"04","open":false,"pId":"4","name":"A部门"},   
{"id":"05","open":false,"pId":"5","name":"A部门"},   
{"id":"06","open":false,"pId":"6","name":"A部门"}
]';
var jsonObj =  JSON.parse(jsonStr);     //转换为json对象
for(var i=0;i<jsonObj.length;i++){
        alert(jsonObj[i].id);           //取id
}