从C＃数组获取平均值 [英] Getting an average from a C# array
问题描述
我已经从事这项工作了几天。我自己编写了所有代码。我并不想欺骗别人，也不想找人替我工作，但是为了我的生命，我无法正常工作。
I have been working on this assignment for a couple days now. I have written all the code myself. I'm not looking to cheat or have someone do my work for me, but for the life of me, I can't get this to work correctly.
我遇到的问题是，当我尝试对数组中的数字求平均时，而不是除以条目数，而是除以允许的条目总数
The problem I'm having is that when I try to average numbers in an array, instead of dividing by just the number of entries, it's dividing by the total allowed entries into the array.
例如。我将2个值输入一个可以容纳100个值的数组，而不是除以2，而是除以100。
For example. I enter 2 values into an array that can hold 100 values, instead of dividing by 2, it divides by 100.
如何将其除以数字的条目？这是我所拥有的：
How do I get it to divide by just the number of entries? Here is what I have:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace ConsoleApplication6
{
class Program
{
static void InputData(string[] player, int[] score, ref int numPlayer)
{
// input items up to the number of the array size
while (numPlayer < player.Length)
{
Console.Write("Enter player name (Q to quit): ");
player[numPlayer] = Console.ReadLine();
if ((player[numPlayer] == "Q") || (player[numPlayer] == "q"))
{
Console.WriteLine();
break;
}
else
{
Console.Write("Enter score for " + player[numPlayer] + ": ");
score[numPlayer] = Convert.ToInt32(Console.ReadLine());
numPlayer++;
}
}
}
static void DisplayPlayerData(string[] player, int[] score, int numPlayer)
{
Console.WriteLine("Name Score");
for (int i = 0; i < numPlayer; i++)
Console.WriteLine("{0, -16} {1, 8}", player[i], score[i]);
}
static double CalculateAverageScore(int[] score, ref int numPlayer)
{
double avgScore;
double total = 0;
for (int i = 0; i < numPlayer; i++)
{
total += score[i];
}
avgScore = total / score.Length;
Console.WriteLine("Average Score:" + avgScore);
return avgScore;
}
static void DisplayBelowAverage(string[] player, int[] score, int numPlayer)
{
double avgScore = CalculateAverageScore(score, ref numPlayer);
Console.WriteLine("Players who scored below average");
Console.WriteLine("Name Score");
for (int i = 0; i < numPlayer; i++)
{
if (score[i] < avgScore)
{
Console.WriteLine("{0, -16} {1}", player[i], score[i]);
}
}
}
static void Main(string[] args)
{
//Variables
string[] player = new string[100];
int[] score = new int[100];
int numPlayer = 0;
InputData(player, score, ref numPlayer);
DisplayPlayerData(player, score, numPlayer);
CalculateAverageScore(score, ref numPlayer);
DisplayBelowAverage(player, score, numPlayer);
Console.ReadLine();
}
}
}
推荐答案
- 您有一个
numPlayer变量代表许多输入的玩家。
只需使用它。 / li>
- You have a
numPlayervariables that stands for a number of entered players.
Just use it.
替换
avgScore = total / score.Length;
与
avgScore = total / numPlayer;
- 您的代码有一些非常奇怪的地方。 / li>
- Your code has some very strange points.
例如，您在计算机中调用 CalculateAverageScore（score，ref numPlayer）; Main（）。但是，您没有使用返回值。在 DisplayBelowAverage 方法中可以正确调用此方法。
通常来说，它看起来是错误的-引用，具有动态数量的值的静态大小的数组，非格式控制台写入行等。
For example, you call CalculateAverageScore(score, ref numPlayer); in a Main(). However, you are not using a return value. This method is properly called in a DisplayBelowAverage method.
In general, it looks wrong - refs, static-sized array with dynamic number of values, non-format console writeline etc.
仅供参考。请阅读一次。也许有些代码行会为您提供帮助。也许您不会找到新的，未知的或有趣的东西。
这就是我要解决的问题：
Just for you information. Read this once. Maybe some code lines will help you. Maybe, you won't find something new, unknown or interesting.
This is how I would solve this problem:
public class Program
{
private const string InputTerminationString = "Q";
public static void Main()
{
List<Player> players = new List<Player>(); // p. 1, 4
while (true)
{
Console.Write("Enter player name ({0} to quit): ", InputTerminationString);
string name = Console.ReadLine();
if (name == InputTerminationString) break; // p. 2
Console.Write("Enter score for {0}: ", name); // p. 3
int score = int.Parse(Console.ReadLine());
players.Add(new Player { Name = name, Score = score });
}
Console.WriteLine("Name Score");
players.ForEach(x => Console.WriteLine("{0, -16} {1, 8}", x.Name, x.Score)); // p. 5
double average = players.Average(x => x.Score); // p. 6
Console.WriteLine("Average score: {0:F2}", average); // p. 3
Console.WriteLine("Players who scored below average");
Console.WriteLine("Name Score");
players
.Where(x => x.Score < average) // p. 7
.ToList()
.ForEach(x => Console.WriteLine("{0, -16} {1, 8}", x.Name, x.Score)); // p. 5
}
}
public class Player
{
public string Name { get; set; }
public int Score { get; set; }
}
现在，逐步：
-
使用
Player类。传递两个独立的名称和分数的数组非常不方便。而且，这通常是不安全和适当的。如果是单个玩家，则玩家的姓名和分数是属性，应存储在struct或class中。
Use
Playerclass. It is pretty inconvenient to pass two independent arrays ofnamesandscores. Moreover, it is not safe and proper in general. A name and a score of a player are properties if a single player and should be stored together either in struct or class.
使用常量。如果您需要将'Q'终止字符串更改为'Exit'，则可以在一秒钟内完成此操作，而无需浏览代码。
Use constants. If you need to change 'Q' termination string to 'Exit', you will be able to do this in a second without looking through the code.
使用格式为 Console.WriteLine 。它像 String.Format 一样工作，您不需要连接字符串。
这里的一些信息： https://msdn.microsoft.com/en-us/library/828t9b9h（v = vs。 110）.aspx
Use formatted Console.WriteLine. It works liks String.Format and you don't need to concatenate strings.
Some info here: https://msdn.microsoft.com/en-us/library/828t9b9h(v=vs.110).aspx
使用动态集合 List 。数组非常适合存储和快速访问已知长度的值范围。由于用户一个一个地输入值，因此您永远不会知道他将输入0、1还是90000个值。 列表集合将为您提供帮助。
此处的一些信息： http://www.dotnetperls.com/list
Use dynamic collection List. Array is good for storing and rapid accessing to range of values of known length. Since a user enters values one by one, you never know if he will enter 0, 1 or 90000 values. List collection will help you with it.
Some info here: http://www.dotnetperls.com/list
您可以使用ForEach方法，该方法为每个代码执行给定的代码集合中的项目。在Lambda表达式中使用ForEach可使代码更短且更具可读性。 .110）.aspx rel = nofollow> https://msdn.microsoft.com/en-us/library/bwabdf9z（v = vs.110）.aspx
You can use ForEach method which executes the given code for every item in a collection. Using ForEach with lambda-expressions makes code shorter and more readable.
Some info here: https://msdn.microsoft.com/en-us/library/bwabdf9z(v=vs.110).aspx
使用平均值函数来计算集合的平均值。如果 int [] ，则可以使用 arr.Average（）。但是，对于 Class 对象，您需要使用lambda-expression描述平均值计算的逻辑。
这里的一些信息： http://www.dotnetperls.com/average
Use Average function which calculates the average of a collection. In case of int[] you can use arr.Average(). However, in case of Class object, you need to describe the logic of calculation of average value using lambda-expression.
Some info here: http://www.dotnetperls.com/average
LINQ 其中表达式可让您过滤集合。
此处的一些信息： http://www.dotnetperls.com/where
LINQ Where expression lets you filter your collection.
Some info here: http://www.dotnetperls.com/where
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