java - 创建一个实现一些自己的方法的接口(interface)

Question

我想创建一个接口(interface)，在 Java 中实现它自己的一些方法(但该语言不允许这样做，如下所示):

//Java-style pseudo-code
public interface Square {
    //Implement a method in the interface itself
    public int getSize(){//this can't be done in Java; can it be done in C++?
        //inherited by every class that implements getWidth()
        //and getHeight()       
        return getWidth()*getHeight();
    }
    public int getHeight();
    public int getWidth();
}

//again, this is Java-style psuedocode
public class Square1 implements Square{

    //getSize should return this.getWidth()*this.getHeight(), as implemented below

    public int getHeight(){
        //method body goes here
    }

    public int getWidth{
        //method body goes here
    }
}

是否可以在 C++ 中创建一个可以实现其自身方法的接口(interface)的等效项？

Answer 1

使用抽象类:

public abstract class Square {

    public abstract int getHeight();

    public abstract int getWidth();

    public int getSize() {
        return getWidth() * getHeight();
    }
}