Question

代码有什么问题？它不会让我为每一个编写输入。我想阅读每个版本的版本数量，年份和城市，它会跳转到循环中，不会让我输入。

public class Competition {

    private static ArrayList<Edition> editions = new ArrayList<Edition>();
    private static Scanner scan = new Scanner(System.in);

    public static void main(String[] args) {

        String newCity = null;
        int newYear = 0;
        int itineration = 0;
        int numberEditions = 0;
        Edition newEdition = new Edition(newCity, newYear);

        System.out.println("How many editions would you like to create?");
        numberEditions = scan.nextInt();

        while (itineration < numberEditions) {
            System.out.println("\nEnter the city and year of the Edition you would"
                    + " like to create: ");

            System.out.println("Year: ");
            newYear = scan.nextInt();
            System.out.println("City: ");
            newCity = scan.nextLine();

            editions.add(newEdition);
            itineration++;
        }

        for (int index = 0; index < editions.size(); index++) {
            System.out.println("Music Festival'" + editions.get(index).getYear()
                    + ", "
                    + editions.get(index).getCity());

        }
    }
}

Answer 1

您需要在阅读年份后消耗额外的费用。您还需要为每个输入创建新版本并将其添加到while循环列表中：

while (itineration < numberEditions) {
    System.out.println("\nEnter the city and year of the Edition you would"
            + " like to create: ");

    System.out.println("Year: ");
    newYear = scan.nextInt();

    scan.nextLine();

    System.out.println("City: ");
    newCity = scan.nextLine();

    Edition newEdition = new Edition(newCity, newYear);
    editions.add(newEdition);
    itineration++;
}

希望有所帮助

Answer 2

您需要在while循环中创建Edition的新实例。

    while (itineration < numberEditions) {
        System.out.println("\nEnter the city and year of the Edition you would"
                + " like to create: ");

        System.out.println("Year: ");
        newYear = scan.nextInt();
        System.out.println("City: ");
        newCity = scan.nextLine();

       Edition newEdition = new Edition(newCity, newYear);
        editions.add(newEdition);
        itineration++;
    }

Answer 3

如果您不知道如何使用Scanner类，则会出现一些问题。 Some people suggest using a buffered reade河我建议在使用任何一个之前研究这两个对象。

Answer 4

你犯了2个错误。

在循环中创建新版本实例
使用Scanner.next()获取输入String。 Scanner.nextLine()无效。

工作代码：

 while (itineration < numberEditions)
        {
            System.out.println("\nEnter the city and year of the Edition you would" + " like to create: ");

            System.out.println("Year: ");
            newYear = scan.nextInt();
            System.out.println("City: ");
            newCity = scan.next();

            editions.add(new Edition(newCity, newYear));
            itineration++;
        }

Answer 5

为Scanner创建新的对象。现在你可以输入值。

newCity = new Scanner(System.in).nextLine();

用Java扫描线

5 个答案: