使用Javascript访问JSON对象中的值

var jsonStr = '{"name":"John", "age":30, "city":"New York"}';
var jsonObj = JSON.parse(jsonStr);

var name = jsonObj.name;
console.log(name); // 输出：John

var firstName = jsonObj["first name"];
console.log(firstName); // 输出：John

var jsonStr = '{"name":"John", "age":30, "address":{"city":"New York", "country":"USA"}}';
var jsonObj = JSON.parse(jsonStr);

var city = jsonObj.address.city;
console.log(city); // 输出：New York

var jsonStr = '{"name":"John", "age":30, "hobbies":["reading", "music", "sports"]}';
var jsonObj = JSON.parse(jsonStr);

var hobby = jsonObj.hobbies[0];
console.log(hobby); // 输出：reading