遍历JSON数据

const json = {
  "name": "John",
  "age": 30,
  "city": "New York"
};

for (let key in json) {
  console.log(key + ": " + json[key]);
}

// 输出：
// name: John
// age: 30
// city: New York

import json

json_data = '{"name": "John", "age": 30, "city": "New York"}'
data = json.loads(json_data)

for key, value in data.items():
    print(key + ": " + str(value))

# 输出：
# name: John
# age: 30
# city: New York

import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;

String json = "{\"name\": \"John\", \"age\": 30, \"city\": \"New York\"}";
ObjectMapper objectMapper = new ObjectMapper();
JsonNode jsonNode = objectMapper.readTree(json);

jsonNode.fields().forEachRemaining(entry -> {
    System.out.println(entry.getKey() + ": " + entry.getValue());
});

// 输出：
// name: "John"
// age: 30
// city: "New York"