大家帮我看下这是什么错误,谢谢代码:
//定义一个抽象Shape类
abstract class Shape {
int area;//面积
int perim;//周长
void getArea();
void getPerim();
}//继承Shape类,定义Rectangle类
class Rectangles extends Shape
{
int length = 3,width = 4; public void getArea(){
area = length * width;
System.out.println("Rectangle's area : " + area);
} public void getPerim(){
perim = 2 * (length + width);
System.out.println("Rectangle's area : " + perim);
}
}//继承Shape类,定义Cirle类
class Circle extends Shape
{
int r = 2;
float PI = 3.14; public void getArea(){
area = int(PI * r *r);
System.out.println("Circle's area : " + area);
} public void getPerim(){
perim = int(2 * PI * r);
System.out.println("Circle's perim : " + perim);
}
}//继承Rectangle类,定义Square类class ShapeClass
{
public static void main(String[] args){ System.out.println("Test Shape:"); Rectangles r = new Rectangles();
r.getArea();
r.getPerim(); Circle c = new Circle();
c.getArea();
c.getPerim(); // Square s = new Square();
// s.getArea();
// s.getPerim();
}
}错误提示:
---------- javac ----------
ShapeClass.java:32: 需要 ".class"
area = int(PI * r *r);
^
ShapeClass.java:32: 不是语句
area = int(PI * r *r);
^
ShapeClass.java:32: 需要 ';'
area = int(PI * r *r);
^
ShapeClass.java:37: 需要 ".class"
perim = int(2 * PI * r);
^
ShapeClass.java:37: 不是语句
perim = int(2 * PI * r);
^
ShapeClass.java:37: 需要 ';'
perim = int(2 * PI * r);
^
6 错误输出完成 (耗时: 0 秒)
//定义一个抽象Shape类
abstract class Shape {
int area;//面积
int perim;//周长
void getArea();
void getPerim();
}//继承Shape类,定义Rectangle类
class Rectangles extends Shape
{
int length = 3,width = 4; public void getArea(){
area = length * width;
System.out.println("Rectangle's area : " + area);
} public void getPerim(){
perim = 2 * (length + width);
System.out.println("Rectangle's area : " + perim);
}
}//继承Shape类,定义Cirle类
class Circle extends Shape
{
int r = 2;
float PI = 3.14; public void getArea(){
area = int(PI * r *r);
System.out.println("Circle's area : " + area);
} public void getPerim(){
perim = int(2 * PI * r);
System.out.println("Circle's perim : " + perim);
}
}//继承Rectangle类,定义Square类class ShapeClass
{
public static void main(String[] args){ System.out.println("Test Shape:"); Rectangles r = new Rectangles();
r.getArea();
r.getPerim(); Circle c = new Circle();
c.getArea();
c.getPerim(); // Square s = new Square();
// s.getArea();
// s.getPerim();
}
}错误提示:
---------- javac ----------
ShapeClass.java:32: 需要 ".class"
area = int(PI * r *r);
^
ShapeClass.java:32: 不是语句
area = int(PI * r *r);
^
ShapeClass.java:32: 需要 ';'
area = int(PI * r *r);
^
ShapeClass.java:37: 需要 ".class"
perim = int(2 * PI * r);
^
ShapeClass.java:37: 不是语句
perim = int(2 * PI * r);
^
ShapeClass.java:37: 需要 ';'
perim = int(2 * PI * r);
^
6 错误输出完成 (耗时: 0 秒)
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改后的为
abstract class Shape {
int area;//面积
int perim;//周长
abstract void getArea();
abstract void getPerim();
} //继承Shape类,定义Rectangle类
class Rectangles extends Shape
{
int length = 3,width = 4; public void getArea(){
area = length * width;
System.out.println("Rectangle's area : " + area);
} public void getPerim(){
perim = 2 * (length + width);
System.out.println("Rectangle's area : " + perim);
}
} //继承Shape类,定义Cirle类
class Circle extends Shape
{
int r = 2;
float PI = (float) 3.14; public void getArea(){
area = (int) (PI * r *r);
System.out.println("Circle's area : " + area);
} public void getPerim(){
perim = (int) (2 * PI * r);
System.out.println("Circle's perim : " + perim);
}
} //继承Rectangle类,定义Square类 class ShapeClass
{
public static void main(String[] args){ System.out.println("Test Shape:"); Rectangles r = new Rectangles();
r.getArea();
r.getPerim(); Circle c = new Circle();
c.getArea();
c.getPerim(); // Square s = new Square();
// s.getArea();
// s.getPerim();
}
}
abstract class Shape {
int area;//面积
int perim;//周长
void getArea();
void getPerim();
}你这是抽象类不是接口,抽象类中的方法不写abstract不会默认加abstract,你需要自己加上,你改为public abstract void getArea();
public abstract void getPerim();
试试
int area;// 面积 int perim;// 周长 abstract void getArea(); abstract void getPerim();
}
public class Circle extends Shape {
int r = 2; static final double PI = 3.14; public void getArea() {
double area = PI * r * r;
System.out.println("Circle's area : " + area);
} public void getPerim() {
double perim = 2 * PI * r;
;
System.out.println("Circle's perim : " + perim);
}
}
public class Rectangles extends Shape {
int length = 3, width = 4; public void getArea() {
area = length * width;
System.out.println("Rectangle's area : " + area);
} public void getPerim() {
perim = 2 * (length + width);
System.out.println("Rectangle's area : " + perim);
}}
public class ShapeClass {
public static void main(String[] args) { System.out.println("Test Shape:"); Rectangles r = new Rectangles();
r.getArea();
r.getPerim(); Circle c = new Circle();
c.getArea();
c.getPerim(); // Square s = new Square();
// s.getArea();
// s.getPerim();
}
}
Rectangle's area : 12
Rectangle's area : 14
Circle's area : 12.56
Circle's perim : 12.56