Counting how many times a certain char appears in a string before any other char appears

Question

I have many strings. Each string is prepended with at least 1 $. What is the best way to loop through the chars of each string to count how many $\

Answer 1

var str ="hello";
str.Where(c => c == 'l').Count()  // 2

Answer 2

int count = Regex.Matches(myString,"$").Count;

Answer 3

You could use the Count method

var count = mystring.Count(x => x == '$')

Answer 4

public static int GetHowManyTimeOccurenceCharInString(string text, char c)
{
    int count = 0;
    foreach(char ch in text)
    {
        if(ch.Equals(c))
        {
            count++;
        }

    }
    return count;
}

Answer 5

//This code worked for me

class CountOfLettersOfString
{
    static void Main()
    {

        Console.WriteLine("Enter string to check count of letters");
        string name = Console.ReadLine();

        //Method1
        char[] testedalphabets = new char[26];
        int[] letterCount = new int[26];
        int countTestesd = 0;
        Console.WriteLine($"Given String is:{name}");

        for (int i = 0; i < name.Length - 1; i++)
        {
            int countChar = 1;

            bool isCharTested = false;

            for (int j = 0; j < testedalphabets.Length - 1; j++)
            {
                if (name[i] == testedalphabets[j])
                {
                    isCharTested = true;
                    break;
                }
            }

            if (!isCharTested)
            {
                testedalphabets[countTestesd] = name[i];

                for (int k = i + 1; k < name.Length - 1; k++)
                {
                    if (name[i] == name[k])
                    {
                        countChar++;
                    }
                }
                letterCount[countTestesd] = countChar;
                countTestesd++;

            }
            else
            {
                continue;
            }
        }

        for (int i = 0; i < testedalphabets.Length - 1; i++)
        {
            if (!char.IsLetter(testedalphabets[i]))
            {
                continue;
            }
            Console.WriteLine($"{testedalphabets[i]}-{letterCount[i]}");
        }


        //Method2
        var g = from c in name.ToLower().ToCharArray() // make sure that L and l are the same eg
                group c by c into m
                select new { Key = m.Key, Count = m.Count() };

        foreach (var item in g)
        {
            Console.WriteLine(string.Format("Character:{0} Appears {1} times", item.Key.ToString(), item.Count));
        }

        Console.ReadLine();
    }
}

Answer 6

This is a similar Solution to find how many email addresses included in a string. This way is more efficient`

int count = 0;
foreach (char c in email.Trim())
    if (c == '@') count++;