java 最简单的多态运用，还是老出错
PassTest3.java:2: 错误: 缺少方法主体, 或声明抽象
public int getPerimeter();
^
PassTest3.java:3: 错误: 缺少方法主体, 或声明抽象
public int getArea();
^
2 个错误
这是错误提示
abstract class GeometricObject{
public int getPerimeter();
public int getArea();
}
class Rectangle extends GeometricObject{
private int x1;
private int x2;
private int y1;
private int y2;
public Rectangle(int x1,int x2,int y1,int y2){
this.x1=x1;
this.x2=x2;
this.y1=y1;
this.y2=y2;
}
public int getHeight(){
int aHeight=0;
aHeight=Math.abs(x1-x2);
return aHeight;
}
public int getWidth(){
int aWidth=0;
aWidth=Math.abs(y1-y2);
return aWidth;
}
public int getPerimeter(){
return getHeight()*2+getWidth()*2;
}
public int getArea(){
return getHeight()*getWidth();
}
}
public class PassTest3{
public static void main(String[] args){
GeometricObject g=new Rectangle(0,5,1,5);
System.out.println(g.getArea() + "----" + g.getPerimeter());
}
}
PassTest3.java:2: 错误: 缺少方法主体, 或声明抽象
public int getPerimeter();
^
PassTest3.java:3: 错误: 缺少方法主体, 或声明抽象
public int getArea();
^
2 个错误
[解决办法]
abstract class GeometricObject{
public abstract int getPerimeter();
public abstract int getArea();
}
方法写成抽象的
