阿洲程式天地

使用資料結構的程式碼容易添加新的函式，不用變動原本的程式碼，物件導向的程式碼容易添加新類別，不用變動已有的函式

 

1、資料結構：

Public class Square{

  public Point topLeft;

  public double side;

}

Public class Circle{

  public Point center;

  public double radius;

}

 

public class Geometry{

  public  double PI = 3.1515926;

  public double area(Object shape){

    if(shape instanceof Square){

      Square s = (Square)shape;

      return s.side*s.side;

    }

    else if(shape instanceof Circle){

      Circle c = (Circle)shape;

      return PI*c.radius*c.radius;

    }

 

 

2、物件導向：

public class Square implements Shape{

  public Point topLeft;

  public double side;

  public double area(){

     return s.side*s.side;

  }

}

 

public class Circle implements Shape{

  public Point center;

  public double radius;

  public  double PI = 3.1515926;

  public double area(){

     return PI*c.radius*c.radius;

  }

}