Question

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?

Answer 1

The String lib provides an easy way of doing this: string.Split(): if you read the entire string in, C# can automatically split it on every space:

string[] words = reader.ReadToEnd().Split(' ');

The words array now contains all of the words in the file and you can do whatever you want with them.

Additionally, you may want to investigate the File.ReadAllText method in the System.IO namespace – it may make your life much easier for file imports to text.

Edit: I guess this assumes that your file is not abhorrently large; as long as the entire thing can be reasonably read into memory, this will work most easily. If you have gigabytes of data to read in, you’ll probably want to shy away from this. I’d suggest using this approach though, if possible: it makes better use of the framework that you have at your disposal.