Comparing strings and get the first place where they vary from eachother

Question

I want to get the first place where 2 string vary from each other. example: for these two strings: \"AAAB\" \"AAAAC\"

I want to get the result 4.

How do i d

Answer 1

static void Main(string[] args)
{
    Console.WriteLine("enter s1 :");
    string s1 = Console.ReadLine();
    Console.WriteLine("enter s2 :");
    string s2 = Console.ReadLine();

    Console.WriteLine("note: zero means there is *no* first dif index starting from s1 ");    
    Console.WriteLine("first dif index of s1 :{0}", findFirstDifIndex(s1, s2)+1);
}

private static int findFirstDifIndex(string s1, string s2)
{
    for (int i = 0; i