C# program to get extension of a given file

Program

using System;
using System.IO;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main()
        {
            DirectoryInfo d = new DirectoryInfo("sample.txt");

            Console.WriteLine("File extension is : " + d.Extension);
        }
    }
}

Output

File extension is : .txt

It this program we used Extension property of DirectoryInfo, get extension of file "sample.txt", that is ".txt".

Note: In above program, we need to remember, when we use "DirectoryInfo" class, System.IO namespace must be included in the program.