受保护的构造函数的实际用途是什么？ [英] What are practical uses of a protected constructor?

问题描述

为什么会声明一个构造函数受保护？我知道构造函数被声明为私有的，目的是不允许在堆栈上创建它们。

Why would anyone declare a constructor protected? I know that constructors are declared private for the purpose of not allowing their creation on stack.

推荐答案

）一个抽象类，一个受保护的构造函数是完全正确的。在这种情况下，你不希望对象从类中实例化，而只是使用它继承。

When a class is (intended as) an abstract class, a protected constructor is exactly right. In that situation you don't want objects to be instantiated from the class but only use it to inherit from.

还有其他用例，如当一组施工参数应限于派生类。

There are other uses cases, like when a certain set of construction parameters should be limited to derived classes.

这篇关于受保护的构造函数的实际用途是什么？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！