c# - 在 C# 中识别索引越界

Question

所以我有这段代码可以从 txt 中对虚构的人口普查数据进行排序。文件:

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

class Program
{
    const int SIZE = 900;
    const int SIZEDISTRICT = 22;
    const int RANGE = 5;
    static void Main()
    {   
        //These arrays will hold the split data from a text file.
        int[] districtDataD = new int[900];
        string[] districtDataG = new string[900];
        string[] districtDataM = new string[900];
        int[] districtDataA = new int[900];

        //countDistrict will hold how many hypothetical people in each hypothetical district and 
        //ages will hold how many hypothetical people between certain hypothetical ages.
        int[] countDistrict = new int[SIZEDISTRICT];
        int[] ages = new int[RANGE] { 0, 18, 30, 45, 65};


        //Modules
        ReadFile(districtDataD, districtDataG, districtDataM,districtDataA);
        CountPopulation(districtDataD, countDistrict);
        AgeRanges(districtDataA, ages);
        DisplayData(districtDataD, districtDataA, ages);
    }//End Main


    //This module splits and inserts the data into the four first arrays
    static void ReadFile(int[] districtDataD, string[] districtDataG, string[] districtDataM, int[] districtDataA)
    {
        string[] lines = File.ReadAllLines("census.txt");
        int i = 0;

        while (i < SIZE && i < districtDataD.Length)
        {
            foreach (string line in File.ReadAllLines("census.txt"))
            {
                string[] parts = line.Split(',');

                districtDataD[i] = int.Parse(parts[0]);
                districtDataG[i] = parts[1];
                districtDataM[i] = parts[2];
                districtDataA[i] = int.Parse(parts[3]);
                i++;
            }
        }
    }
    //This module counts how many hypothetical people are in each fictional district
   static void CountPopulation(int[] districtDataD, int[] countDistrict)
    {
        int i = 0;
        for (i = 0; i < districtDataD.Length; i++)
        {
            if (districtDataD[i] > 0 && districtDataD[i] < districtDataD.Length)
            {
                countDistrict[districtDataD[i]]
                    ++;
            }
        }
    }


    //This module sorts the ages into 0-18, 19-30, 31-45, 46-65, and 65 and up
     private static void AgeRanges(int[] districtDataA, int[] ages)
     {
         int idx = 0;
         for (idx = 0; idx < districtDataA.Length && ages[idx] > districtDataA[idx]; idx++)
         {

             ages[idx] = districtDataA[idx];
         }
     }


    //This module displays the data
     static void DisplayData(int[] countDistrict, int[] ageDistrict, int[] ages)
    {
        int index = 0;
        for (index = 0; index < countDistrict.Length; index++)
        {
            Console.WriteLine(" District {0}: {1}", index + 1, countDistrict[index]);
        }

        int x = 0;
        for (x = 0; x < ageDistrict.Length; x++)
        {
            Console.WriteLine("Ages under {0} : {1}", ages[x], ageDistrict[x]);
        }
    }
}

我得到索引越界错误，但我不知道在哪里以及如何找到它。

文本。文件目前看起来像这样，但会扩展到包括更多，大约 100 个左右。 900只是作为上限。

21,f,s,14

41,f,m,22

12, 米, 秒, 12

11, f, s, 8

29, 米, 米, 4

6、米、秒、12

9, f, s, 2

30, f, s, 1

Answer 1

如果您不知道数组的长度，请改用集合。这将使您的文件大小与长度无关。使用数组，您必须设置数组的长度，据我所知，它可以根据文件而改变 - 如果没有正确实现，这将始终给您带来索引越界的困难。使用集合可以避免这些问题

List<int> districtDataD = new List<int>();

然后您可以将项目添加到此集合中，例如:

districtDataD.Add(1);