字符计数

Question

Its weird,well i need to count characters from file, and in later computations use that information, now its weird part, i wanted to check if my program is correctly countig appearance of each character so i compared my results with monodevelop matches from ctrl+f for example for 'i' character my result is 518 monodevelop has 561 matches (with case sensitivity on), so maybe it coudl look like my programm does not count well but i made test and rewrited it to another file and again checked matches in mono develop now my results and monodevelop matches where same. Why is it happening ?

here is code

public Histogram (String nazwa)
    {
        histogram = new Dictionary<string,float>();
        StringBuilder plik = odczytPliku.odczyt(nazwa);
        n = 0;
        foreach(char w in plik.ToString())
        {
            if(!histogram.ContainsKey(new string(w,1)))
                histogram.Add(new string(w,1),1);
            else
                histogram[new string(w,1)]+=1;
            n++;
        }

    }

Answer 1

The following code will create a histogram of characters in a string. This assumes you're passing in the string correctly.

public Dictionary<char,int> Histogram( String myString )
{
    Dictionary<char,int> hist = new Dictionary<char,int>()

    if( !String.IsNullOrEmpty(myString) )
    {
        for( int i = 0; i < myString.Length; i++ )
        {
            char c = myString[i];

            if(hist.ContainsKey(c))
            {
                hist[c] = hist[c] + 1;
            }
            else
            {
                hist.Add(c,1);
            }
        }
    }

    return hist;
}

Answer 2

public Dictionary<char, int> Hist(string target)
    {
        return target.GroupBy(c => c)
            .ToDictionary(g => g.Key, g => g.Count());
    }

To make it case insensitive, just call it like this:

var hist = Hist(target.ToUpperInvariant());