获取引用对象id的项

const obj = { id: 123, name: 'John' };
const id = Object.getOwnPropertyNames(obj)[0];
console.log(id); // 输出：id
console.log(obj[id]); // 输出：123

obj = {'id': 123, 'name': 'John'}
id = list(obj.keys())[0]
print(id)  # 输出：id
print(obj[id])  # 输出：123

class MyClass {
    int id;
    String name;
}

MyClass obj = new MyClass();
obj.id = 123;
obj.name = "John";

int id = System.identityHashCode(obj);
System.out.println(id);  // 输出：对象的唯一标识符