我是一个初学者,在学校上CompSci课程。本章是制作子类;然而,该类以某种方式导致程序终止。世界甚至没有出现,也没有错误。(我正在运行Eclipse)。
这是我的代码:
package karel;
import kareltherobot.*;
public class Race implements Directions
{
public static void main(String args[]) {
class Car extends UrRobot
{ public Car(int street, int avenue, Direction direction, int beepers)
{super(5, 5, East, infinity);
}
public void turnAround()
{
turnLeft();
turnLeft();
}
public void turnRight()
{
turnLeft();
turnLeft();
turnLeft();
}
}
{
World.setVisible(true);
World.showSpeedControl(true);
}
{
Car kar = (Car) new UrRobot(5, 5, East, infinity);
kar.move();
kar.turnLeft();
kar.move();
kar.turnAround();
kar.move();
kar.turnRight();
}
}
}
有没有办法让这个程序不出错而终止?
您需要在主函数中运行代码。Java在类主函数中查找并执行代码。试试看,如果不起作用,就回来转发。
尝试以下操作。
import kareltherobot.*;
public class Race implements Directions
{
public Race(){
}
public static void main(String args[]) {
class Car extends UrRobot
{
public Car(int street, int avenue, Direction direction, int beepers)
{
super(street, avenue, direction, beepers);
}
public void turnAround()
{
super.turnLeft();
super.turnLeft();
}
public void turnRight()
{
super.turnLeft();
super.turnLeft();
super.turnLeft();
}
}
World.setVisible(true);
World.showSpeedControl(true);
Car kar = new Car(5, 5, East, 100);
kar.move();
kar.turnLeft();
kar.move();
kar.turnAround();
kar.move();
kar.turnRight();
}
}