jlab0401_3.java

计算机系学习java的专用ppt

class JLab0401_3{
   public static void main(String[] args){
      Rectangle myRect=new Rectangle(2.5,8.7);
      Rectangle Rect=new Rectangle();
      double theArea,newArea;
      theArea=myRect.area();
      newArea=Rect.area();
      System.out.println("My rectangle has width "+myRect.width);
      System.out.println("My rectangle has length "+myRect.length); 
      System.out.println("My rectangle has area "+theArea);
      System.out.println("new rectangle has width "+Rect.width);
      System.out.println("new rectangle has length "+Rect.length); 
      System.out.println("new rectangle has area "+newArea);
      }
     }
 class Rectangle{
   double width,length;
   public Rectangle(double w,double l){
     width=w;
     length=l; 
     }
   public Rectangle(){
      setWidth(3.6);
      setLength(10.8);}
   public void setWidth(double w) {
      width=w;}
   public void setLength(double l){ 
      length=l;}
   public double area(){
     double a;
     a=length*width;
     return a;
     }
    }