Wsrtjtyk

I have text with 600 words and I'm supposed to delete every quotation marks, numbers(years, dates, ..), digits ,... I should only have words, and I have to put in into dictionary.

So I have tried to go through with for each loop and get the first letter and save it in a list. Then I split every row in a word.
e.g.:

You are pretty.

You

are

pretty

The problem there are words in a row they're still same but they shouldn't be same. I've tried to fix it but I couldn't find any solution.

 public Dictionary<string, int> words = new Dictionary<string, int>();

        public Dictionary<char, List<string>> firstletter = new Dictionary<char, List<string>>();

        public Aufgabe(string filename)

        {

            string filler = "ABCDEFGHIJKLMNOPQRSTUVWXYZÄÖÜ";

            foreach (char f in filler)

            {

                firstletter[f] = new List<string>();

            }



            Load(filename);



        }

        public void Load(string filename)

        {

            List<string> w = new List<string>();

            StreamReader r = new StreamReader(filename);







            while (!r.EndOfStream)

            {

                string row = r.ReadLine();

                string parts = row.Split(' ');

                string sonderzeichen = new string { "@", ",", ".", ";", "'", "1", "2", "3", "4", "5", "6", "7", "8", "9", "0", "(", ")", "{",

                    "}", "!", "?", "/", """, "&", "+", "-", "–" };

                string list = new string[parts.Length];

                for (int i = 0; i < parts.Length; i++)

                {

                    string a = parts[i];

                    foreach (string s in sonderzeichen)

                    {

                        if (s != "-")

                        {

                            a = a.Replace(s, string.Empty);

                        }

                        else

                        {

                            if (a.Length == 1)

                            {

                                a = string.Empty;

                            }

                        }

                    }

                    list[i] = a;

                }

                parts = list;



                foreach (string a in parts)

                {

                    if (words.ContainsKey(a))

                    {

                        words[a] += 1;

                    }

                    else

                    {

                        words.Add(a, 1);

                    }



                    string b = a.ToUpper();

                    if (b == "")

                        continue;

                    List<string> letter = firstletter[b[0]];

                    if (!letter.Contains(a))

                    {

                        letter.Add(a);

                    }

                }

            }   

        }

There are some things missing in the other answers:

• No validation is done to check if the text is a word


• Comparison should not be case-sensitive (i.e. spain, Spain and SPAIN should be considered the same word)

My solution:

StringComparer comparer = StringComparer.OrdinalIgnoreCase;

string text = "The 'rain' in spain falls mainly on the plain. 07 November 2018 20:02:07 - 20180520 I said the Plain in SPAIN. 12345";



var dictionary = Regex.Split(text, @"W+")

                      .Where(IsValidWord)

                      .GroupBy(m => m, comparer)

                      .ToDictionary(m => m.Key, m => m.Count(), comparer);

Method IsValidWord:

// logic to validate word goes here

private static bool IsValidWord(string text)

{

    double value;



    bool isNumeric = double.TryParse(text, out value);



    // add more validation rules here



    return !isNumeric;

}

EDIT

I noticed in your code that you have a Dictionary with the words grouped by first letter. This can be achieved like this (using the previous dictionary):

var lettersDictionary = dictionary.Keys.GroupBy(x => x.Substring(0, 1), 

        (alphabet, subList) => new {

            Alphabet = alphabet,

            SubList = subList.OrderBy(x => x, comparer).ToList()

        })

        .ToDictionary(m => m.Alphabet, m => m.SubList, comparer);

You can just split with a regex, then use LINQ to create your dictionary:

var dictionary = Regex.Split(text, @"W+")

    .GroupBy(m => m, StringComparer.OrdinalIgnoreCase) // Case-insensitive

    .ToDictionary(m => m.Key, m => m.Count());

UPDATE

In applying to your example code, your task class could become something like this to build both dictionaries (and to consider case insensitive):

public class Aufgabe

{

    const string ALPHABET = "ABCDEFGHIJKLMNOPQRSTUVWXYZÄÖÜ";

    public Dictionary<string, int> words;

    public Dictionary<char, List<string>> firstletter;

    public Aufgabe(string filename)

    {

        var text = File.ReadAllText(filename);

        words = Regex.Split(text, @"W+")

            .GroupBy(m => m, StringComparer.OrdinalIgnoreCase)

            .ToDictionary(m => m.Key, m => m.Count());

        firstletter = ALPHABET.ToDictionary(a => a, // First-letter key

            a => words.Keys.Where(m => a == char.ToUpper(m[0])).ToList()); // Words

    }

}

Here is one way with Regex, note that case sensitivity has not been addressed

var text = "The 'rain' in spain falls mainly on the plain. I said the plain in spain";



var result = new Dictionary<string,string>();



Regex.Matches(text, @"[^s]+")

     .OfType<Match>()

     .Select(m => Regex.Replace(m.Value, @"W", string.Empty))

     .ToList()

     .ForEach(word =>

     {

        if (!result.ContainsKey(word))

            result.Add(word, word);

     });

result