用cmd 不能運行，請問如何改正才能用cmd 運行
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("矩形周長為"+c);
? return c;}
public double S(){
System.out.println("面積為"+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("圓形周長為"+c);}
?public double S(){
System.out.println("面積為"+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();}
}
2017-06-04
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("圓形周長為"+c);}
在這段代碼中 return c 應(yīng)放在System.out.println("圓形周長為"+c);后面。
這是我運行的結(jié)果：矩形周長為13.2
????????????????????????????????面積為9.450000000000001
????????????????????????????????圓形周長為13.188
????????????????????????????????面積為13.8474