public function iBfunc2(){echo "in iBfunc2";} } 三、 抽象类和接口的异同 1. 相同点: (1) 两者都是抽象类,都不能实例化。 (2) interface 实现类及 abstract class 的子类都必须要实现已经声明的抽象方法。 2. 不同点: (1) interface 需要实现,要用 implements ,而 a
interface用在當一個物件須和其他物件共同合作時,為了確保其他物件有我想要的method,所以定下interface要該物件遵守,在Design Pattern到處可以看到這種應用,如strategy,bridge,prototype...。 而abstract class是用在整個繼承體系的最上層,用來定義出整個繼承體系該有哪些method,子類別可以對這些method加以override,或維持和a...
抽象类你就不能再多重继承了 The functions in java interface is like virtual functions in C++. We can not implement the detail things in these functions. It seems that, if there is a class A1 inherited from abstract class A, A has method1(detail implementation) , but A1 has not method1 ...
跟interface相关的还有一个话题是wrapper class,也很精彩,它是把继承转成合成的方式,应用了decorater模式的思想. 在书里的第16章介绍。 1://Wrapper class - uses composition in place of inheritance2:publicclassInstrumentedSet<E>extendsForwardingSet<E>{3:privateintaddCount = 0;4:publicInstrumentedSet(Set<...
2. Interface Interfaces are yet another basic building block of most Java APIs.An Interface defines contracts, which implementing classes need to honor. These contracts are essentially unimplemented methods. Java already has a keyword for unimplemented methods i.e.abstract. In Java, a class can imp...
In C++, we use terms abstract class and interface interchangeably. A class with pure virtual function is known as abstract class. For example the following function is a pure virtual function: virtual void fun() = 0; A pure virtual function is marked with a virtual keyword and has = 0 af...
(3)在abstractclass中可以有自己的数据成员,也可以有非abstarct的成员方法,而在interface中,只能够有静态的不能被修改的数据成员(也就是必须是staticfinal的,不过在interface中一般不定义数据成员),所有的成员方法默认都是publicabstract类型的。(4)abstractclass和interface所反映出的设计理念不同。其实abstractclass表示...
The basic purpose of using abstract classes is to maintain a uniform interface inside all derived classes. This means if there are two classes inheriting from an abstract class, both classes should provide the implementation of a pure virtual function; otherwise, they will become abstract. It ...
interfaceShape { doubleArea{get;} voidDraw(); } classCircle:Shape { privatereadonlyintradius; publicdoubleArea=>Math.PI*Math.Pow(radius,2); publicvoidDraw() { //do something } } After refactoring abstractclassShape { publicabstractdoubleArea{get;} ...
1. python class的继承 python允许多根继承, 这点像C++, 但不像C++那样变态, 需区分公有继承/私有继承/保护继承, python只有一种继承方式。也许正因为支持多重继承, 因此python没有interface这个关键词. 2. 给类起个别名 在python中, class也是对象, 所以你可以像操作对象一样, 将class赋值给一个对象, 这样就...