Question

创建外部Car类和驱动程序CarDemo类。更改CarDemo类的说明包括两个方法（getInputYear（）返回1940年到2016年之间的年份，getInputMake（）返回汽车的品牌并检查空字符串）。

它编译时没有错误，但它只询问年份模型输入，然后自己打印出其他所有内容。

public class Car
{
    private int yearModel;
    private String make;
    private int speed;

    // initialize variables

    Car(int y, String m)
{
        yearModel = y;
        make = m;
        speed = 0;
}

    // setYear method
    public void setYearModel(int y)
{
        yearModel = y;
}
    // setMake method
    public void setMake(String m)
{           make = m;

}

    // set speed method
    public void setSpeed(int s)
    {
        speed = s;
    }

    // getYearModel method
    public int getYearModel()
    {
        return yearModel;
    }
    // getMake method
    public String getMake()
    {
        return make;
    }
    // getSpeed method
    public int getSpeed()
    {
        return speed;
    }
    // accelerate method accelerates the car's speed by 5

    public void accelerate()
    {
        speed += 5;
    }

    // brake method decreases the car's speed by 5

    public void brake()
    {
        speed -= 5;
    }

}

这是DemoCar类

import java.util.Scanner;

public class CarDemo

{

    public static void main(String[] args)

    {
                Car yourCar;
                String make;
                double yearModel, speed;
                Scanner sc = new Scanner(System.in);

             System.out.print("What is the car's year model? ");
             yearModel = sc.nextDouble();

             System.out.print("What is the make of the car? ");
             make = sc.nextLine();


            yourCar = new Car(0, make);

            System.out.println("Current status of the car:");
            System.out.println("Year model: " + yourCar.getYearModel());
            System.out.println("Make: " + yourCar.getMake());
            System.out.println("Speed: " + yourCar.getSpeed());

        // Accelerate the car five times.

        System.out.println("Speed up!");
        System.out.println();
        for(int i=0; i<5; i++)

        {


            yourCar.accelerate();
            System.out.println("demoCar's speed " + yourCar.getSpeed());// Display the speed.

        }
        System.out.println();
        // Brake the car five times.
        System.out.println("Slow down!");
        System.out.println();
        for(int i=0; i<5; i++)

        {

            yourCar.brake();

            System.out.println("demoCar's speed " + yourCar.getSpeed());// Display the speed.

        }

    }

}

Answer 1

sc.nextDouble();没有处理换行符，而你的sc.nextLine()消耗了它，并跳过其余部分。

您可以再添加一个nextLine()来捕获剩余的换行符。

         System.out.print("What is the car's year model? ");
         yearModel = sc.nextDouble();

         boolean isInRange = (1940 <= yearModel） && (yearModle <= 2016);

         if(!isInRange){
             // not in range
             return;
         }

         sc.nextLine(); // consumes the left-over newline character.

         System.out.print("What is the make of the car? ");
         make = sc.nextLine();

<强>替代地：

   System.out.print("What is the make of the car? ");
   make = sc.nextLine();

将sc.nextLine()更改为sc.next()

方法next()找到并返回此扫描程序中的下一个完整令牌。

创建不同的类，CarDemo类和Car类

1 个答案: