simple solution for characters frequency in string object

问题

The task what I'm trying to do is about showing up the frequency of every single characters from the string object, for the moment I've done some part of code, just doesn't have the easy concept in my mind for finishing this task. So far I was thinking that it might be usefull to changing the char into int type. What is worth mentioning I'd like to avoid using the part: if (letter == 'a') NumberCount++; as if it wouldnt be efficient to write that much conditions for that simple task, and I'was thinking of doing it way mentioned above. I'd be gratefull for any sugestions of how to code it further.....I'm beginner at c#

 class Program
 {
    static void Main(string[] args)
    {
       string sign = "attitude";
       for (int i = 0; i < sign.Length; i++)
       {
          int number = sign[i]; // changing char into int

       }

回答1:

Here's a non Linq way to get the counts of all the unique letters.

var characterCount= new Dictionary<char,int>();
foreach(var c in sign)
{
    if(characterCount.ContainsKey(c))
        characterCount[c]++;
    else
        characterCount[c] = 1;
}

Then to find out how many "a"s there are

int aCount = 0;
characterCount.TryGetValue('a', out aCount);

Or to get all the counts

foreach(var pair in characterCount)
{
    Console.WriteLine("{0} - {1}", pair.Key, pair.Value);
}

回答2:

You can easily do it using Linq like:

 string sign = "attitude";
 int count = sign.Count(x=> x== 'a');

or if you want all characters count then:

 string sign = "attitude";
 var alphabetsCount = sign.GroupBy(x=> x)
                          .Select(x=>new 
                                    {
                                      Character = x.Key, 
                                      Count = x.Count()
                                    });

Here is a working Example

UPDATE:

Without Linq you can do it with a loop and track it in a dictionary like:

string sign = "attitude";
Dictionary<char,int> dic = new Dictionary<char,int>();
foreach(var alphabet in sign)
{
    if(dic.ContainsKey(alphabet))
        dic[alphabet] = dic[alphabet] +1;
    else
        dic.Add(alphabet,1);
}

Here is Demo without Linq using Dictionary<>

回答3:

If you're looking to do it without Linq, then try

var charDictionary = new Dictionary<char, int>();
string sign = "attitude";
foreach(char currentChar in sign)
{
    if(charDictionary.ContainsKey(currentChar))
    { charDictionary[currentChar]++; }
    else
    { charDictionary.Add(currentChar, 1); }
}

回答4:

class Program
    {
        static void Main(string[] args)
        {

            char ch;
            Console.Write("Enter a string:");
            string str = Console.ReadLine();
            for (ch = 'A'; ch <= 'Z'; ch++)
            {
                int count = 0;
                for (int i = 0; i < str.Length; i++)
                {
                    if (ch==str[i] || str[i] == (ch + 32))
                    {
                        count++;
                    }
                }
                if (count > 0)
                {
                    Console.WriteLine("Char {0} having Freq of {1}", ch, count);
                }
            }
            Console.Read();
        }
    }

来源：https://stackoverflow.com/questions/31863204/simple-solution-for-characters-frequency-in-string-object

标签

character

frequency