Helps with reading word by word

I have a text file containing just lowercase letters and no punctuation except for spaces. I would like to know the best way of reading the file char by char, in a way that if the next char is a space, it signifies the end of one word and the start of a new word. i.e. as each character is read it is added to a string, if the next char is space, then the word is passed to another method and reset until the reader reaches the end of the file.

I’m trying to do this with a StringReader, something like this:

public String GetNextWord(StringReader reader)
{
    String word = "";
    char c;
    do
    {
        c = Convert.ToChar(reader.Read());
        word += c;
    } while (c != ' ');
    return word;
}

and put the GetNextWord method in a while loop till the end of the file. Does this approach make sense or are there better ways of achieving this?

I would do something like this:

IEnumerable<string> ReadWords(StreamReader reader)
{
    string line;
    while((line = reader.ReadLine())!=null)
    {
        foreach(string word in line.Split(new [1] {' '}, StringSplitOptions.RemoveEmptyEntries))
        {
            yield return word;
        }
    }
}

If to use reader.ReadAllText it loads the entire file into your memory so you can get OutOfMemoryException and a lot of other problems.

answered Mar 16, 2012 at 16:21

If you want to read it whitout spliting the string — for example lines are too long, so you might encounter OutOfMemoryException, you should do it like this (using streamreader):

while (sr.Peek() >= 0)
{
    c = (char)sr.Read();
    if (c.Equals(' ') || c.Equals('t') || c.Equals('n') || c.Equals('r'))
    {
        break;
    }
    else
        word += c;
}
return word;

answered Aug 28, 2014 at 9:09

This is method that will split your words, while they are separated by space or more than 1 space (two spaces for example)/

StreamReader streamReader = new StreamReader(filePath); //get the file
string stringWithMultipleSpaces= streamReader.ReadToEnd(); //load file to string
streamReader.Close();

Regex r = new Regex(" +"); //specify delimiter (spaces)
string [] words = r.Split(stringWithMultipleSpaces); //(convert string to array of words)

foreach (String W in words)
{
   MessageBox.Show(W);
}

answered Mar 16, 2012 at 16:08

I created a simple console program on your exact requirement with the files you mentioned, It should be easy to run and check. Please find attached the code. Hope this helps

static void Main(string[] args)
    {

        string[] input = File.ReadAllLines(@"C:UsersachikhaleDesktopfile.txt");
        string[] array1File = File.ReadAllLines(@"C:UsersachikhaleDesktoparray1.txt");
        string[] array2File = File.ReadAllLines(@"C:UsersachikhaleDesktoparray2.txt");

        List<string> finalResultarray1File = new List<string>();
        List<string> finalResultarray2File = new List<string>();

        foreach (string inputstring in input)
        {
            string[] wordTemps = inputstring.Split(' ');//  .Split(' ');

            foreach (string array1Filestring in array1File)
            {
                string[] word1Temps = array1Filestring.Split(' ');

                var result = word1Temps.Where(y => !string.IsNullOrEmpty(y) && wordTemps.Contains(y)).ToList();

                if (result.Count > 0)
                {
                    finalResultarray1File.AddRange(result);
                }

            }

        }

        foreach (string inputstring in input)
        {
            string[] wordTemps = inputstring.Split(' ');//  .Split(' ');

            foreach (string array2Filestring in array2File)
            {
                string[] word1Temps = array2Filestring.Split(' ');

                var result = word1Temps.Where(y => !string.IsNullOrEmpty(y) && wordTemps.Contains(y)).ToList();

                if (result.Count > 0)
                {
                    finalResultarray2File.AddRange(result);
                }

            }

        }

        if (finalResultarray1File.Count > 0)
        {
            Console.WriteLine("file array1.txt contians words: {0}", string.Join(";", finalResultarray1File));
        }

        if (finalResultarray2File.Count > 0)
        {
            Console.WriteLine("file array2.txt contians words: {0}", string.Join(";", finalResultarray2File));
        }

        Console.ReadLine();

    }
}

answered Sep 18, 2017 at 7:19

This code will extract words from a text file based on the Regex pattern. You can try playing with other patterns to see what works best for you.

    StreamReader reader =  new StreamReader(fileName);

    var pattern = new Regex(
              @"( [^W_d]              # starting with a letter
                                        # followed by a run of either...
                  ( [^W_d] |          #   more letters or
                    [-'d](?=[^W_d])  #   ', -, or digit followed by a letter
                  )*
                  [^W_d]              # and finishing with a letter
                )",
              RegexOptions.IgnorePatternWhitespace);

    string input = reader.ReadToEnd();

    foreach (Match m in pattern.Matches(input))
        Console.WriteLine("{0}", m.Groups[1].Value);

    reader.Close();       

answered Sep 25, 2017 at 17:43