Count Number of Occurrences of Each Character in a?

String
Dictionary<char, int> CountCharacters(string s)
{
var dict = new Dictionary<char, int>();
foreach (char c in s)
{
if (dict.ContainsKey(c))

dict[c]++;

else

dict[c] = 1;
}
return dict;
}

Explanation:

Simple frequency map using Dictionary.