如何访问json中的数据？

{
  "name": "John",
  "age": 25,
  "email": "john@example.com"
}

var jsonStr = '{"name":"John","age":25,"email":"john@example.com"}';
var jsonObj = JSON.parse(jsonStr);

console.log(jsonObj.name);  // 输出：John
console.log(jsonObj.age);   // 输出：25
console.log(jsonObj.email); // 输出：john@example.com

import json

json_str = '{"name":"John","age":25,"email":"john@example.com"}'
json_obj = json.loads(json_str)

print(json_obj['name'])   # 输出：John
print(json_obj['age'])    # 输出：25
print(json_obj['email'])  # 输出：john@example.com

{
  "person": {
    "name": "John",
    "age": 25,
    "email": "john@example.com"
  }
}

var jsonStr = '{"person":{"name":"John","age":25,"email":"john@example.com"}}';
var jsonObj = JSON.parse(jsonStr);

console.log(jsonObj.person.name);   // 输出：John
console.log(jsonObj.person.age);    // 输出：25
console.log(jsonObj.person.email);  // 输出：john@example.com