迭代文件夹中的多个txt文件以在C＃中读取它们

Question

Problem: I need to iterate through multiple files in a folder and read them. They are .txt files. While reading I need to note what words occured in each file.

For example:

File 1 text: "John is my friend friend" -> words: John, is, my, friend

File 2 text: "John is Mark" -> words: John, is, Mark

Currently I was reading files and then making it one big file, but it does not work like this so I have to read them separately. Old idea:

string[] filesZ = { "1.txt", "2.txt" };

var allLinesZ = filesZ.SelectMany(i => System.IO.File.ReadAllLines(i));
System.IO.File.WriteAllLines("n.txt", allLinesZ.ToArray());

var logFileZ = File.ReadAllLines("n.txt");

So this is the first question, how to iterate through them and reading all of them without making a big file.

The second one will be how to make a counter to all of the words for seperate files, currently for one big file I am using:

var logFileZ = File.ReadAllLines("n.txt");

List<string> LogListZ = new List<string>(logFileZ);

var fi = new Dictionary<string, int>();
LogListZ.ForEach(str => AddToDictionary(fi, str));

foreach (var entry in fi)
{
    Console.WriteLine(entry.Key + ": " + entry.Value);
}

This is AddToDictionary:

static void AddToDictionary(Dictionary<string, int> dictionary, string input)
{
    input.Split(new[] { ' ', ',', '.', '?', '!', '.' }, StringSplitOptions.RemoveEmptyEntries).ToList().ForEach(n =>
    {
        if (dictionary.ContainsKey(n))
            dictionary[n]++;
        else
            dictionary.Add(n, 1);
    });
}

I was thinking about making a loop through all the files (is it possible?) and inside make a counter that counts word for example John in how many files it was. I don't need a specific file number, just a number of occurence of a word, without counting (like in example file 1) words twice (friend).

Answer 1

You don't have to do much for part one of your question: remove WriteAllLines , remove the ReadAllLines for "n.txt" , rename allLinesZ variable to logFileZ , and add ToList or ToArray call:

var logFileZ = filesZ
    .SelectMany(i => System.IO.File.ReadAllLines(i))
    .ToList();

You can make a counter in one go as well: split each string as you go, feed it to SelectMany , use GroupBy , and convert to dictionary using Count() as the value:

var counts = filesZ
    .SelectMany(i => System.IO.File.ReadAllLines(i)
        .SelectMany(line => line.Split(new[] { ' ', ',', '.', '?', '!', '.' })
        .Distinct())
    .GroupBy(word => word)
    .ToDictionary(g => g.Key, g => g.Count());

The call of Distinct() ensures that the same word will not be counted twice if it's in a single file.