在fieldname=>fieldvalue关键字中有效地获取数据

# 使用字典
data = {
    "name": "Alice",
    "age": 30,
    "city": "New York"
}

# 获取数据
print(data["name"])  # 输出: Alice

// 使用对象
let data = {
    name: "Alice",
    age: 30,
    city: "New York"
};

// 获取数据
console.log(data.name);  // 输出: Alice

import java.util.HashMap;
import java.util.Map;

public class Main {
    public static void main(String[] args) {
        // 使用HashMap
        Map<String, Object> data = new HashMap<>();
        data.put("name", "Alice");
        data.put("age", 30);
        data.put("city", "New York");

        // 获取数据
        System.out.println(data.get("name"));  // 输出: Alice
    }
}

if "name" in data:
    print(data["name"])
else:
    print("Key not found")

if (data.hasOwnProperty("name")) {
    console.log(data.name);
} else {
    console.log("Key not found");
}

if (data.containsKey("name")) {
    System.out.println(data.get("name"));
} else {
    System.out.println("Key not found");
}