count how many times a character is present

Question

using System;

class HelloWorld
{
    static void Main(String[] args)
    {
        countSearchCharInInString("Stanley",'s'); //return 1
    }

    //inString = "Stanley", searchChar = 't', return 1
    static int countSearchCharInInString(string inString, char searchChar)
    {
        foreach (char letter in countSearchCharInInString 
        {
            for (int i = 0; i = inString.lengeth; i++) 
            {
                string count = inString{i}
                if (count = searchChar)
                string newString = [];
                newString.Add(count);
                console.writeline(newString.length)
            }
        };
        return 0;
    }
}

I am trying to count how many times the letter s is present in this string name Stanley. I havent used c# in a while and was wondering if there was ashorter way of doing this. Also, this doesn't work I know but it was just me brainstorming the concept. Any help would be greatly appreciated.