Json字符串和Json对象相互转换

字符串-->json对象：JSON.parse() 

var str = '{"code":"A001","name":"张三"}';
JSON.parse(str);
结果： 
code: "A001"
name: "张三"

json对象-->字符串：JSON.stringify()

var obj = {code:"A001",name:"张三"};
JSON.stringify(obj);
结果： 
"{"code":"A001","name":"张三"}"