c# - ユーザー入力を使用して配列を更新および変更するにはどうすればよいですか

Question

以前にこの質問をしたことがありますが、どこにも行けなかったので、もう一度質問すると、コードの別の部分が機能するようになったので、誰かが助けてくれるかもしれません。そのため、エントリを更新および削除する方法を知る必要があります。ユーザー入力のみでこれを行いたいことを明確にしたいと思います。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace PlayerSystem6
{
    class Program
    {
        static void Main(string[] args)
        {
            //The MAXPLAYERS constant is the physical table size
            const Int32 MAXPLAYERS = 23;

            //Declare the player tables
            Int32[] playerNumbers = new Int32[MAXPLAYERS];
            String[] playerLastNames = new String[MAXPLAYERS];
            Int32[] playerPoints = new Int32[MAXPLAYERS];

            //Keep track of the actual number of players (i.e. logical table size)
            Int32 playerCount = 0;

            //Main Driver
            char menuItem;
            Console.WriteLine("Welcome to the player system...\n");
            menuItem = GetMenuItem();
            while (menuItem != 'X')
            {
                ProcessMenuItem(menuItem, playerNumbers, playerLastNames, playerPoints, ref playerCount, MAXPLAYERS);
                menuItem = GetMenuItem();
            }
            Console.WriteLine("\nThank you, goodbye");
            Console.ReadLine();
        }

        //Returns either a 'C', 'R', 'U', 'D', 'L', or 'X' to the caller
        static char GetMenuItem()
        {
            char menuItem;
            DisplayMenu();
            menuItem = char.ToUpper(char.Parse(Console.ReadLine()));
            while (menuItem != 'C' && menuItem != 'R' //JG
                && menuItem != 'L' && menuItem != 'X' && menuItem != 'U')
            {
                Console.WriteLine("\nError - Invalid menu item");
                DisplayMenu();
                menuItem = char.ToUpper(char.Parse(Console.ReadLine()));
            }
            return menuItem;
        }

        static void DisplayMenu()
        {
            Console.WriteLine("\nPlease pick an item:");
            Console.WriteLine("C - Create Player");
            Console.WriteLine("R - Retrieve Player");
            Console.WriteLine("U - Update Player");
            Console.WriteLine("D - Delete Player");
            Console.WriteLine("L - List Players");
            Console.WriteLine("X - Exit");
        }

        //Routes to the appropriate process routine based on the user menu choice
        static void ProcessMenuItem(Char menuItem, Int32[] playerNumbers, String[] playerLastNames,
            Int32[] playerPoints, ref Int32 playerCount, Int32 MAXPLAYERS)
        {
            switch (menuItem)
            {
                case 'C':
                    ProcessCreate(playerNumbers, playerLastNames, playerPoints, ref playerCount, MAXPLAYERS);
                    break;
                case 'L':
                    ProcessList(playerNumbers, playerLastNames, playerPoints, playerCount);
                    break;
                case 'R': //JG
                    ProcessRetrieve(playerNumbers, playerLastNames, playerPoints, ref playerCount, MAXPLAYERS);
                    break;
                case 'U':
                    ProcessUpdate(playerNumbers, playerLastNames, playerPoints, playerCount, MAXPLAYERS);
                    break;

            }
        }

        //Creates a player in the tables if the array is not already full and the name is not a duplicate
        static void ProcessCreate(Int32[] playerNumbers, String[] playerLastNames,
            Int32[] playerPoints, ref Int32 playerCount, Int32 MAXPLAYERS)
        {
            Int32 number, points;
            String lastName;
            if (playerCount < MAXPLAYERS)
            {
                number = GetPositiveInteger("\nCreate Player: please enter the player's number");
                if (GetPlayerIndex(number, playerNumbers, playerCount) == -1)
                {
                    lastName = GetString("\nCreate Player: please enter the player's last name");
                    points = GetPositiveInteger("\nCreate Player: please enter the player's points");
                    InsertPlayer(number, lastName, points, playerNumbers, playerLastNames, playerPoints, ref playerCount);
                    Console.WriteLine("\nCreate Player: Number - {0}, Name - {1}, Points - {2}, created successfully", number, lastName, points);
                    Console.WriteLine();
                }
                else
                    Console.WriteLine("\nCreate Player: the player number already exists");
            }
            else
                Console.WriteLine("\nCreate Player: the player roster is already full");

        }

        //Inserts the player at the correct location in the tables based on order of 
        //ascending player number. Unless the insert location is at the end, this 
        //requires shifting existing players down in order to make room 
        static void InsertPlayer(Int32 number, String lastName, Int32 points,
            Int32[] playerNumbers, String[] playerLastNames, Int32[] playerPoints,
            ref Int32 playerCount)
        {
            /* PUTS DATA IN NEXT AVALIABLE SLOT
            playerNumbers[playerCount] = number;
            playerLastNames[playerCount] = lastName;
            playerPoints[playerCount] = points;
            playerCount++;
            */

            // PUTS DATA IN PLAYER ASECENDING ORDER
            Int32 insertIndex, shiftCount;
            insertIndex = GetInsertIndex(number, playerNumbers, playerCount);
            for (shiftCount = playerCount; shiftCount > insertIndex; shiftCount--)
            {
                playerNumbers[shiftCount] = playerNumbers[shiftCount - 1];
                playerLastNames[shiftCount] = playerLastNames[shiftCount - 1];
                playerPoints[shiftCount] = playerPoints[shiftCount - 1];
            }
            playerNumbers[insertIndex] = number;
            playerLastNames[insertIndex] = lastName;
            playerPoints[insertIndex] = points;
            playerCount++;

        }
        //Returns the index of the first player number in the table that is greater
        //than the player number to be inserted
        static Int32 GetInsertIndex(Int32 playerNumber, Int32[] playerNumbers,
            Int32 playerCount)
        {
            Int32 index = 0;
            bool found = false;
            while (index < playerCount && found == false)
                if (playerNumbers[index] > playerNumber)
                    found = true;
                else
                    index++;
            return index;
        }

        //Returns the index of the player number in the table 
        //or -1 if the number is not found
        static Int32 GetPlayerIndex(Int32 playerNumber,
            Int32[] playerNumbers, Int32 playerCount)
        {
            Int32 index = 0;
            bool found = false;
            while (index < playerCount && found == false)
                if (playerNumbers[index] == playerNumber)
                    found = true;
                else
                    index++;
            if (found == false)
                index = -1;
            return index;
        }

        //Lists the players in the tables
        static void ProcessList(Int32[] playerNumbers, String[] playerLastNames,
            Int32[] playerPoints, Int32 playerCount)
        {

            if (playerCount > 0)
            {
                Console.WriteLine("\n{0,7}   {1,-25}{2,6}\n", "Number", "Last Name", "Points");
                for (Int32 player = 0; player < playerCount; player++)
                    Console.WriteLine("{0,7}   {1,-25}{2,6}", playerNumbers[player], playerLastNames[player], playerPoints[player]);
            }
            else
                Console.WriteLine("\nList Players: the roster is empty");
        }

        //Returns a positive integer
        static Int32 GetPositiveInteger(String prompt)
        {
            Int32 n;
            Console.WriteLine(prompt);
            n = Int32.Parse(Console.ReadLine());
            while (n < 0)
            {
                Console.WriteLine("\nError: enter positive value");
                Console.WriteLine(prompt);
                n = Int32.Parse(Console.ReadLine());
            }
            return n;
        }

        //Returns a non-empty string
        static String GetString(String prompt)
        {
            String returnString;
            Console.WriteLine(prompt);
            returnString = Console.ReadLine();
            while (returnString == "")
            {
                Console.WriteLine("\nError: must enter keyboard data");
                Console.WriteLine(prompt);
                returnString = Console.ReadLine();
            }
            return returnString;
        }
        // retrieve single value from an array

        //static void ProcessRetrieve(Int32[] playerNumbers, String[] playerLastNames
        //, Int32[] playerPoints, Int32 playerCount)
        //{

        //}

したがって、ここで、機能する単一のエントリを取得するプロセスを開始します。これは、次の 2 つの関数で動作するように変更することで再利用できる関数です。

        static void ProcessRetrieve(Int32[] playerNumbers, String[] playerLastNames,
            Int32[] playerPoints, ref Int32 playerCount, Int32 MAXPLAYERS)
        {
            int player;// Player number to find
            int playerindex;//index of the player number in Array
            if (playerCount < MAXPLAYERS)
            {
                player = GetPositiveInteger("\nRetrieve Player: please enter the player's number"); //JG I used the same mechanism when you are creating the record, when you create yu check if it exists
                /** If it exists you say record exists in this case I said display the existing record**/
                playerindex = GetPlayerIndex(player, playerNumbers, playerCount);
                if (playerindex != -1)// !-1 means Does not exist JG
                {

                    Console.WriteLine("{0,7}   {1,-25}{2,6}", playerNumbers[playerindex], playerLastNames[playerindex], playerPoints[playerindex]);
                    Console.WriteLine();
                }
                else
                    Console.WriteLine("\nRetrieve Player: the player number does not exists");
            }
            else
                Console.WriteLine("\nRetrieve Player: the player does not exist in the roster");
        }

ここで私は問題を抱えています。取得する代わりにこのコードを更新するにはどうすればよいですか

        static void ProcessUpdate(Int32[] playerNumbers,
        string[] playerLastnames, Int32[] playerpoints, Int32 playerCounts, Int32 MAXPLAYERS)
        {
            int player;// Player number to find
            int playerindex;//index of the player number in Array
            if (playerCounts < MAXPLAYERS || playerCounts == MAXPLAYERS)
            {
                player = GetPositiveInteger("\nUpdate Player: please enter the player's number");
                playerindex = GetPlayerIndex(player, playerNumbers, playerCounts);
                if (playerindex != -1)
                {

                    Console.WriteLine("{0,7}   {1,-25}{2,6}", playerNumbers[playerindex], playerLastnames[playerindex], playerpoints[playerindex]);
                    Console.WriteLine();
                }
                else
                    Console.WriteLine("\nUpdate Player: the player number does not exists");
            }
            else
                Console.WriteLine("\nUpdate Player: the player does not exist in the roster");
        }

    }
}

Answer 1

コードには、更新関数を作成するために必要な構成要素が既に含まれています。これらが何であるかを見てみましょう。

1. 最初にプレイヤー番号を尋ねる必要があります。これはすでに ProcessUpdate メソッドに実装されています。

           player = GetPositiveInteger("\nUpdate Player: please enter the player's number");
   

2. プレイヤー番号に一致する配列インデックスを見つける必要があります。これは、ProcessUpdate メソッドにも既に実装されています。

           playerindex = GetPlayerIndex(player, playerNumbers, playerCounts);
   

3. ユーザーに新しいプレーヤー データを要求する必要があります。これはすでに ProcessCreate メソッドに実装されています。文字列のみを変更して、更新されたデータを要求していることを明確にします。

               lastName = GetString("\nUpdate Player: please enter the player's updated last name");
               points = GetPositiveInteger("\nUpdate Player: please enter the player's updated points");
   

4. 最後に、ユーザーから取得したデータを配列に入れる必要があります。これはすでに InsertPlayer に実装されています。ここでは、正しい変数名を使用することに注意を払います。

       playerLastNames[playerindex] = lastName;
       playerPoints[playerindex] = points;
   

これをすべて (変数宣言とサニティ チェックを含めて) まとめると、ProcessUpdate メソッドは次のようになります。

    static void ProcessUpdate(Int32[] playerNumbers,
    string[] playerLastnames, Int32[] playerpoints, Int32 playerCounts, Int32 MAXPLAYERS)
    {
        int player;// Player number to find
        int playerindex;//index of the player number in Array

        String lastName;
        int points;

        if (playerCounts < MAXPLAYERS || playerCounts == MAXPLAYERS)
        {
            player = GetPositiveInteger("\nUpdate Player: please enter the player's number");
            playerindex = GetPlayerIndex(player, playerNumbers, playerCounts);
            if (playerindex != -1)
            {
                lastName = GetString("\nUpdate Player: please enter the player's updated last name");
                points = GetPositiveInteger("\nUpdate Player: please enter the player's updated points");

                playerLastNames[playerindex] = lastName;
                playerPoints[playerindex] = points;

            }
            else
                Console.WriteLine("\nUpdate Player: the player number does not exists");
        }
        else
            Console.WriteLine("\nUpdate Player: the player does not exist in the roster");
        }
    }

一般的に言えば、プログラムの構造は正しい方法の例ではありません (申し訳ありません)。しかし、私はあなたのプログラミングコースについて知りません。コースでは、構造体、オブジェクト (オブジェクト指向プログラミング)、または辞書などのその他の "高度な" データ型を既にカバーしていますか? または、これらは将来のトピックになりますか? 3 つの配列を使用する必要があることはわかっていますが、すでに構造体だけを使用することで、要件を満たしながらコードを大幅にクリーンアップできます。

Answer 2

以下に、ユーザー入力によってプレーヤーのスコアと名前を更新する方法の例を書きました。数字、名前、ポイントのインデックスをプレーヤーごとに同じインデックスに保持することで、それらを追跡できます。

// Make sure the indexes of the arrays are aligned with the player array 
// (to keep track which points are for which player)
int[] playerNums = new int[10];
string[] playerNames = new string[10];
int[] playerPoints = new int[10];

// We now add the user here (you do it somewhere from user input)
playerNums[0] = 1;
playerNames[0] = "Tim";
playerPoints[0] = 10;

char key = Console.ReadKey(true).KeyChar;
if (char.IsDigit(key))
{
    // We get the number from the char.
    int inputNum = int.Parse(key.ToString());

    // We make sure the user isn't giving an index past the length of our arrays
    // (which are 10 in size).
    if (inputNum > -1 && inputNum < playerNums.Length - 1)
    {
        playerNames[inputNum] = "John"; // Tim now becomes John.
        playerPoints[inputNum] += 5; // Increase John's score.
    }
}

これがあなたが探していた答えだったか教えてください。

Answer 3

配列の代わりに、次のようにディクショナリを使用するため、すべての配列のインデックスを維持する必要がなく、特定の要素を検索する場合は非常に簡単です。また、プレーヤー番号はすべてのプレーヤー情報のキーであり、任意のキーを選択できます。詳細については、以下のリンクを参照してください http://www.dotnetperls.com/dictionary

名前空間プレーヤー{クラスプログラム{

    static void Main(string[] args)
    {
        Dictionary<string, PlayerInfo> info = new Dictionary<string, PlayerInfo>();
        for (int i = 0; i < 10; i++)
        {
            Console.WriteLine("Enter Player Number");
            string playerNumber = Console.ReadLine();
            info.Add(playerNumber, new PlayerInfo());
            Console.WriteLine("Enter Player Name");
            info[playerNumber].PlayerName = Console.ReadLine(); 
            Console.WriteLine("Enter Player Points");
            info[playerNumber].points = Console.ReadLine(); 
        }

        Console.WriteLine("Enter the player number to be deleted");
        string playerNumberToDelete = Console.ReadLine();
        info.Remove(playerNumberToDelete);

        Console.WriteLine("Enter a player number to update");
        string playerNumberToUpdate = Console.ReadLine();
        Console.WriteLine("Enter Player Name");
        info[playerNumberToUpdate].PlayerName = Console.ReadLine();
        Console.WriteLine("Enter Player Points");
        info[playerNumberToUpdate].points = Console.ReadLine();

        Console.WriteLine("Enter player number dispaly deatils");
        string playerNumberToDisplay = Console.ReadLine();
        Console.WriteLine("Name " + info[playerNumberToDisplay].PlayerName);
        Console.WriteLine("Points " + info[playerNumberToDisplay].points);
    }
}
class PlayerInfo
{
    public string PlayerName;
    public string points;
}

}