How to reverse a string :

class Program

{
  static void Main(string[] args)
  {
    string reverseName = " ";
    Console.WriteLine("Please give an input :");
    string fullName = Console.ReadLine();   //Take user input.

    for (int index = fullName.Length - 1; index >= 0; index--)
    {
      reverseName = reverseName + fullName[index];
    }
    

    Console.WriteLine(reverseName);
    Console.ReadLine();
  }    

}

Input :       I am a student.

Output :    .tneduts a ma I