Java从用户创建一个字符串数组

Question

我正试图弄清楚如何在这个梦幻足球节目中添加新功能。我希望能够让用户为他们的团队输入名称，而不仅仅是“团队 1”、“团队 2”等。我正在尝试创建一个字符串数组和

1. 询问用户团队名称
2. 在接下来的问题中列出团队名称，询问每周的分数
3. 在程序结束时列出最终结果统计中的团队名称

经过大量搜索和阅读，我无法弄清楚如何做到这一点。我目前在 for 循环中向用户询问团队名称，我在其中询问每周的分数，但这似乎不是放置它的正确位置。任何帮助将不胜感激。

import java.util.Scanner;

public class fantasyFootball
{

  private int numberOfTeams; // Same as teamAverage.length.
  private int numberOfWeeks; // Same as weekAverage.length.

  private int[][] score; //numberOfTeams rows and numberOfWeeks columns.
  private int[] teamAverage;
  private int[] scoreAverage;

  public static void main(String[] args)
  {
    fantasyFootball book = new fantasyFootball( );
    book.display();
  }

  public fantasyFootball(int[][] a)
  {
    if (a.length == 0 || a[0].length == 0)
    {
        System.out.println("Empty score records. Aborting.");
        System.exit(0);
    }

    numberOfTeams = a.length;
    numberOfWeeks = a[0].length;
    fillScore(a);
    fillTeamAverage( );
    fillScoreAverage( );
  }

  public fantasyFootball(fantasyFootball book)
  {
    numberOfTeams = book.numberOfTeams;
    numberOfWeeks = book.numberOfWeeks;
    fillScore(book.score);
    fillTeamAverage( );
    fillScoreAverage( );
  }

  public fantasyFootball( )
  {
    Scanner keyboard = new Scanner(System.in);

    System.out.println("Enter number of teams:");
    numberOfTeams = keyboard.nextInt( );

    System.out.println("Enter number of weeks:");
    numberOfWeeks = keyboard.nextInt( );

    score = new int[numberOfTeams][numberOfWeeks];

    for (int teamName = 1; 
            teamName <= numberOfTeams; teamName++)
        for (int weekNumber = 1; 
                weekNumber <= numberOfWeeks; weekNumber++)
        {
            System.out.println("Enter team name ");
            teamName.add(keyboard.nextLine()); 
            System.out.println("Enter score for team "
                    + teamName);
            System.out.println("on week number " + weekNumber);
            score[teamName - 1][weekNumber - 1] =
                    keyboard.nextInt( );
        }

    fillTeamAverage( );
    fillScoreAverage( );
  }

  private void fillScore(int[][] a)
  {
    score = new int[numberOfTeams][numberOfWeeks];

    for (int teamName = 1; 
            teamName <= numberOfTeams; teamName++)
    {
        for (int weekNumber = 1; 
                weekNumber <= numberOfWeeks; weekNumber++)
            score[teamName][weekNumber] = 
            a[teamName][weekNumber];
    }
  }

/**
  Fills the array teamAverage using the data from the array score.
 */
  private void fillTeamAverage( )
  {
    teamAverage = new int[numberOfTeams];

    for (int teamName = 1; 
            teamName <= numberOfTeams; teamName++)
    {//Process one teamName:
        int sum = 0;
        for (int weekNumber = 1; 
                weekNumber <= numberOfWeeks; weekNumber++)
            sum = sum + score[teamName - 1][weekNumber - 1];
        //sum contains the sum of the week scores for team number teamName.
        teamAverage[teamName - 1] = sum/numberOfWeeks;
        //Average for team teamNumber is teamAverage[teamNumber - 1]
    }
  }

/**
  Fills the array scoreAverage using the data from the array score.
 */
  private void fillScoreAverage( )
  {
    scoreAverage = new int[numberOfWeeks];

    for (int weekNumber = 1; weekNumber <= numberOfWeeks; weekNumber++)
    {//Process one week (for all teams):
        int sum = 0;
        for (int teamName = 1; 
                teamName <= numberOfTeams; teamName++)
            sum = sum + score[teamName - 1][weekNumber - 1];
        //sum contains the sum of all team scores on week number weekNumber.
        scoreAverage[weekNumber - 1] = sum/numberOfTeams;
        //Average for week weekNumber is the value of weekAverage[weekNumber - 1]
    }
  }

  public void display( )
  {
    for (int teamName = 1; 
            teamName <= numberOfTeams; teamName++)

    {//Display for one teamNumber:
        System.out.print("Team " + teamName + " Weeks: ");
        for (int weekNumber = 1; 
                weekNumber <= numberOfWeeks; weekNumber++)
            System.out.print(score[teamName - 1][weekNumber - 1] + " ");
        System.out.println(" Ave = " + teamAverage[teamName - 1] );
    }

    System.out.println("Week averages: ");
    for (int weekNumber = 1; weekNumber <= numberOfWeeks; weekNumber++)
        System.out.print("Week " + weekNumber 
                + " Ave = " + scoreAverage[weekNumber - 1] + " ");
    System.out.println( );
}

  private void teamName()
  {
    Scanner keyboard = new Scanner(System.in);
    String[] teamName = new String[3];

  }

}

Answer 1

这是使用ArrayList 存储团队名称的解决方案：

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class fantasyFootball {

    private List<String> teamNames = new ArrayList<String>();
    private int numberOfTeams; // Same as teamAverage.length.
    private int numberOfWeeks; // Same as weekAverage.length.

    private int[][] score; // numberOfTeams rows and numberOfWeeks columns.
    private int[] teamAverage;
    private int[] scoreAverage;

    public static void main(String[] args) {
        fantasyFootball book = new fantasyFootball();
        book.display();
    }

    public fantasyFootball(int[][] a) {
        if (a.length == 0 || a[0].length == 0) {
            System.out.println("Empty score records. Aborting.");
            System.exit(0);
        }

        numberOfTeams = a.length;
        numberOfWeeks = a[0].length;
        fillScore(a);
        fillTeamAverage();
        fillScoreAverage();
    }

    public fantasyFootball(fantasyFootball book) {
        numberOfTeams = book.numberOfTeams;
        numberOfWeeks = book.numberOfWeeks;
        fillScore(book.score);
        fillTeamAverage();
        fillScoreAverage();
    }

    public fantasyFootball() {
        Scanner keyboard = new Scanner(System.in);

        System.out.println("Enter number of teams:");
        numberOfTeams = keyboard.nextInt();

        System.out.println("Enter number of weeks:");
        numberOfWeeks = keyboard.nextInt();

        score = new int[numberOfTeams][numberOfWeeks];

        for (int teamName = 1; teamName <= numberOfTeams; teamName++){
            System.out.println("Enter team " + teamName + " name ");
            String name = keyboard.next();
            teamNames.add(name);
            for (int weekNumber = 1; weekNumber <= numberOfWeeks; weekNumber++) {
                System.out.println("Enter score for team " + teamName + " on week number " + weekNumber);
                score[teamName - 1][weekNumber - 1] = keyboard.nextInt();
            }
        }

        fillTeamAverage();
        fillScoreAverage();
    }

    private void fillScore(int[][] a) {
        score = new int[numberOfTeams][numberOfWeeks];

        for (int teamName = 1; teamName <= numberOfTeams; teamName++) {
            for (int weekNumber = 1; weekNumber <= numberOfWeeks; weekNumber++)
                score[teamName][weekNumber] = a[teamName][weekNumber];
        }
    }

    /**
     * Fills the array teamAverage using the data from the array score.
     */
    private void fillTeamAverage() {
        teamAverage = new int[numberOfTeams];

        for (int teamName = 1; teamName <= numberOfTeams; teamName++) {// Process
                                                                        // one
                                                                        // teamName:
            int sum = 0;
            for (int weekNumber = 1; weekNumber <= numberOfWeeks; weekNumber++)
                sum = sum + score[teamName - 1][weekNumber - 1];
            // sum contains the sum of the week scores for team number teamName.
            teamAverage[teamName - 1] = sum / numberOfWeeks;
            // Average for team teamNumber is teamAverage[teamNumber - 1]
        }
    }

    /**
     * Fills the array scoreAverage using the data from the array score.
     */
    private void fillScoreAverage() {
        scoreAverage = new int[numberOfWeeks];

        for (int weekNumber = 1; weekNumber <= numberOfWeeks; weekNumber++) {// Process
                                                                                // one
                                                                                // week
                                                                                // (for
                                                                                // all
                                                                                // teams):
            int sum = 0;
            for (int teamName = 1; teamName <= numberOfTeams; teamName++)
                sum = sum + score[teamName - 1][weekNumber - 1];
            // sum contains the sum of all team scores on week number
            // weekNumber.
            scoreAverage[weekNumber - 1] = sum / numberOfTeams;
            // Average for week weekNumber is the value of
            // weekAverage[weekNumber - 1]
        }
    }

    public void display() {
        for (int teamName = 1; teamName <= numberOfTeams; teamName++)

        {// Display for one teamNumber:
            System.out.print("Team " + teamNames.get(teamName-1) + " Weeks: ");
            for (int weekNumber = 1; weekNumber <= numberOfWeeks; weekNumber++)
                System.out.print(score[teamName - 1][weekNumber - 1] + " ");
            System.out.println(" Ave = " + teamAverage[teamName - 1]);
        }

        System.out.println("Week averages: ");
        for (int weekNumber = 1; weekNumber <= numberOfWeeks; weekNumber++)
            System.out.print("Week " + weekNumber + " Ave = "
                    + scoreAverage[weekNumber - 1] + " ");
        System.out.println();
    }

    private void teamName() {
        Scanner keyboard = new Scanner(System.in);
        String[] teamName = new String[3];

    }
}

输出：

Enter number of teams:
3
Enter number of weeks:
2
Enter team 1 name 
MyTeam1
Enter score for team 1 on week number 1
1
Enter score for team 1 on week number 2
2
Enter team 2 name 
MyTeam2
Enter score for team 2 on week number 1
3
Enter score for team 2 on week number 2
4
Enter team 3 name 
MyTeam3
Enter score for team 3 on week number 1
4
Enter score for team 3 on week number 2
6
Team MyTeam1 Weeks: 1 2  Ave = 1
Team MyTeam2 Weeks: 3 4  Ave = 3
Team MyTeam3 Weeks: 4 6  Ave = 5
Week averages: 
Week 1 Ave = 2 Week 2 Ave = 4 

Answer 2

我会在获得分数之前设置团队名称，

System.out.println("Enter number of teams:");
int numberOfTeams = keyboard.nextInt( );

String[] teamNames = new String[numberOfTeams];
for (int i = 0; i < numberOfTeams; i++) {
  System.out.printf("Enter team name for team %d:%n", 1+i);
  teamNames[i] = keyboard.next();
}

Answer 3

        System.out.println("Enter team name ");
        teamName.add(keyboard.nextLine()); 
        System.out.println("Enter score for team "
                + teamName);

改为：

        System.out.println("Enter team name ");
        String name = (keyboard.nextLine()); 
        System.out.println("Enter score for team "
                + name);

另外，如果你想存储它：

private String[] names = new String[numberOfTeams];
//Then in the above code:
names[teamName] = name;

Answer 4

这是一个使用简单字符串对象数组的解决方案。将private String[] names; 添加到您的实例字段列表中，使 FantasyFootball 构造函数如下所示：

public FantasyFootball()
{
    int numTeams;
    int numWeeks;
    Scanner keyboard = new Scanner(System.in);

    System.out.print("Enter number of teams: ");
    numTeams = keyboard.nextInt();

    for (int i = 0; i < numTeams; i++)
    {
        System.out.print("Enter the name of team " + (i+1) + ": ");
        names[i] = keyboard.nextLine();
    }

    System.out.print("Enter number of weeks: ");
    numWeeks = keyboard.nextInt();

    names = new String[numTeams];
    scores = new int[numTeams][numWeeks];

    for (int i = 0; i < numTeams; i++)
    {
        for (int j = 0; j < numWeeks; j++)
        {
            System.out.print("Enter the score for " + names[i] + " for week " + (j+1) + ": ");
            scores[i][j] = keyboard.nextInt();
        }
    }

    fillTeamAverage();
    fillScoreAverage();
}

一些编程技巧：

首先，我建议创建一个 Team 对象，其中包含一组每周得分、一个 int 代表团队平均值和一个 int 代表平均得分。然后在您的 FantasyFootball 类中，只需操作一个 Team 对象数组，而不是每个不同字段的数组。它使将来的一切工作变得更容易。

按照惯例，类名通常以大写字母开头。几乎每个人都遵循惯例，所以我强烈建议你也这样做。

不可否认，使用 one-liner-so-I-don't-need-braces 语法更短，但它使代码更难阅读，更难调试代码，所以我也建议你使用所有的大括号，以及将左大括号放在新行而不是语句行的末尾。同样，它会让事情变得更容易。

最后，在 Java 中，您可以使用 + 运算符将变量连接到字符串上，如您所知。但我注意到在您的代码中，您将一些打印内容分解为两个调用。您可能已经知道这一点，但是您可以在同一个字符串/打印语句中使用多个 + 运算符，就像在数字中使用 + 一样。

希望这会有所帮助！