我的代碼如下
package?com.imooc;
import?java.util.Scanner;
public?class?Test?{
public?static?void?main(String[]?args)?{
Scanner?input?=?new?Scanner(System.in);
System.out.println("請輸入圓的半徑：");
double?radius?=?input.nextDouble();
System.out.println("請輸入矩形的長：");
double?ll?=?input.nextDouble();
System.out.println("請輸入矩形的寬：");
double?ww?=?input.nextDouble();
Shape?sha?=?new?Rectangle(ll,ww);
sha.Perimeter();
sha.area();
Shape?sha1?=?new?Circle(radius);
sha1.Perimeter();
sha1.area();
}
}
2015-08-07
package?com.imooc; public?abstract?class?Shape?{ public?abstract?void?Perimeter(); public?abstract?void?area(); }2015-08-07
package?com.imooc; public?class?Rectangle?extends?Shape?{ public?double?l; public?double?w; public?Rectangle(double?length2,double?wide2){ l?=?length2; w?=?wide2; if(l?<?0){ System.out.println("你輸入的長度有誤，請重新輸入"); } if(w?<?0){ System.out.println("你輸入的寬度有誤嗎，請重新輸入"); } } public?void?Perimeter(){ double?a?=?2*(l?+?w); System.out.println("矩形的周長="+a); } public?void?area()?{ //?TODO?Auto-generated?method?stub double?b?=?l?*?w; System.out.println("矩形的面積="+b); } }2015-08-07
package?com.imooc; public?class?Circle?extends?Shape?{ double?radius; public?Circle(double?r){ radius?=?r; if?(radius?<?0)?{ System.out.println("你輸入的半徑有誤。請重新輸入"); } } public?void?Perimeter(){ //double?e?=?3.14; double?a?=?2*radius*3.14; System.out.println("圓的周長="+a); } public?void?area()?{ //?TODO?Auto-generated?method?stub double?b?=?3.14?*radius*radius; System.out.println("圓的面積="+b); } }