数组以及如何更新、删除和检索条目
本文关键字：删除 检索 更新 何更新 数组 | 更新日期: 2023-09-27 18:35:55
嗨，我有一个任务，我必须创建一个程序，其中包含三个数组，一个用于
姓氏，一个用于得分，一个用于玩家编号，现在我已经完成了所有数组和事情，但我对如何检索条目、更新条目或删除条目感到困惑，到目前为止，我可以使用的选项是创建播放器， 列出玩家并退出另外两个我不知道该怎么做，一些正确方向的指导真的会有所帮助，谢谢。
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 != 'L' && menuItem != 'X')
{
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;
}
}
//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;
}
}
}
不能在 C# 数组中添加或删除值。数组具有固定大小。也就是说，您可以更改任何元素的值，并且可以将新数组（减号和元素或附加元素）重新分配给原始变量。
int[] IDs = new int[] { 1, 2, 3 };
IDs[2] = 55; // was 3
IDs = new [] { 1, 2, 4, 5, 6 };
您还可以查看可以从中插入、更新或删除的通用列表List<>()。