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源自:10-3 Java 中的抽象类

用cmd 不能运行,请问如何改正才能用cmd 运行

public abstract class  shape{

   public abstract double  C();

   public abstract double  S();}

public class Rectaugle extends shape {

  double a=4.5;

  double b=2.1;

   double   c=(a+b)*2;

  double  s=a*b;

 public double C (){

System.out.println("矩形周长为"+c);

  return c;}

public double S(){

System.out.println("面积为"+s);

  return s;}

   }

public class Circle extends shape  {

  final double p=3.14;

  double r=2.1;

  double  c=2*p*r;

  double    s=p*r*r;

  public double C(){

  return c;

 System.out.println("圆形周长为"+c);}

 public double S(){

System.out.println("面积为"+s);

 return s;}

}

public class Hello{

 public static void main (String [] args){

 shape s1=new Rectaugle();

 shape s2=new Circle();

 s1.C();

 s1.S();

 s2.C();

 s2.S();}

}


提问者:慕粉2110022127 2017-06-04 16:52

个回答

  • Esc丶粲然
    2017-06-04 17:49:35

    public class Circle extends shape  {

      final double p=3.14;

      double r=2.1;

      double  c=2*p*r;

      double    s=p*r*r;

      public double C(){

      return c;

     System.out.println("圆形周长为"+c);}

    在这段代码中 return c 应放在System.out.println("圆形周长为"+c);后面。

    这是我运行的结果:矩形周长为13.2

                                    面积为9.450000000000001

                                    圆形周长为13.188

                                    面积为13.8474