第五章作业题第二题

abstract class A

{

public abstract void f(int x);

public abstract void g(int x,int y);

public abstract double h(double x);

}

class B extends A{

int a,b;

double k;

public void f(int x){

a=x;

System.out.printf("a=%d\n",a);

}

public void g(int x,int y){

a=x;

b=y;

System.out.printf("a=%d,b=%d\n",a,b);

}

public double h(double x){

k=x;

System.out.printf("k=%f\n",k);

return k;

}

}

class C extends A{

int a,b;

double k;

public void f(int x){

a=x;

System.out.printf("a=%d\n",a);

}

public void g(int x,int y){

a=x;

b=y;

System.out.printf("a=%d,b=%d\n",a,b);

}

public double h(double x){

k=x;

System.out.printf("k=%f\n",k);

return k;

}

}

class D extends A{

double a;

int t,y;

public void f(int x){

t=x;

System.out.printf("t=%d\n",t);

}

public void g(int x,int y){

t=x;

this.y=y;

System.out.printf("t=%d,y=%d\n",t,y);

}

public double h(double x){

a=x;

return a;

}

}

public class K{

public static void main(String args[]){

A a;

a=new B();

System.out.println("正方形的边长:");

a.f(10);

a=new C();

System.out.println("长方形的长和宽:");

a.g(12,8);

a=new D();

System.out.println("梯形的高\n"+a.h(22.88));

}

}

结果：

正方形的边长:

a=10

长方形的长和宽:

a=12,b=8

梯形的高

22.88