C# Program to Print Fibonacci Series

The Fibonacci sequence is a sequence where the next number is the sum of the previous two numbers. The first two numbers of fibonacci series are 0 and 1.

C# Fibonacci Series up to n terms

 private static void Main(string[] args)
        {
            int i, num, num1 = 0, num2 = 1;
            int nextNum = num1 + num2;

            Console.WriteLine("Enter the number of terms: ");
            num = int.Parse(Console.ReadLine());

            Console.Write("Fibonacci Series: {0}, {1}, ", num1, num2);

            // print 3rd to nth terms
            for (i = 3; i <= num; ++i)
            {
                Console.Write("{0}, ", nextNum);
                num1 = num2;
                num2 = nextNum;
                nextNum = num1 + num2;
            }
            Console.ReadLine();
        }

Output:

C# Fibonacci Series Up to nth Number

 private static void Main(string[] args)
        {
            int num, num1 = 0, num2 = 1;
            int nextNum = num1 + num2;

            Console.WriteLine("Enter the number: ");
            num = int.Parse(Console.ReadLine());

            Console.Write("Fibonacci Series: {0}, {1}, ", num1, num2);
            while (nextNum <= num)
            {
                Console.Write("{0}, ", nextNum);
                num1 = num2;
                num2 = nextNum;
                nextNum = num1 + num2;
            }
            Console.ReadLine();
        }

Output: