protected field的用法和樣例：
例句
- A protected field can be accessed by any method in the class in which it is declared or by any method defined in subclasses of that class.
聲明該欄位的類中的任何方法或者該類子類中定義的任何方法都可以訪問受保護欄位。 - A protected field can be accessed by any method in the class in which it is declared or by any method defined in subclasses of that class.
聲明該欄位的類中的任何方法或者該類子類中定義的任何方法都可以訪問受保護欄位。
