## Computing Fibonacci Series using Recursion in Java

Recursion
means a method; calling directly or indirectly themselves. Recursion is a
useful programming technique. In some cases, it enables you to develop a
straightforward and simple solution to an otherwise difficult problem.
This post introduces you how to

**Fibonacci Series using Recursion in Java.**Actually the Fibonacci series was named for Leonardo Fibonacci, a medieval mathematician.
The Fibonacci Series

**of can be defined as follows:**
0 1 1 2 3 5 8 13 21 34 55 89 ...

The Fibonacci series begins with 0 and 1, and each subsequent number is the sum of the preceding two. The series can be recursively defined as follows:

fib(0) = 0;

fib(1) = 1;

fib(index) = fib(index - 2) + fib(index - 1); index >= 2

fib(1) = 1;

fib(index) = fib(index - 2) + fib(index - 1); index >= 2

**import**java.util.Scanner;

**public**

**class**CalculateFibonacci {

**public**

**static**

**void**main(String args[]) {

// Create a Scanner

Scanner
input =

**new**Scanner(System.*in*);
System.

*out*.print("Enter an index for the Fibonacci number: ");**int**index = input.nextInt();

System.

*out*.println("Fibonacci number at index " + index + " is "
+

*fib*(index));
}

/** The method for
finding the Fibonacci number */

**public**

**static**

**long**fib(

**long**index) {

**if**(index == 0) {

// Base case

**return**0;

}

**else****if**(index == 1) {
// Base case

**return**1;

}

**else**{
// Reduction and
recursive calls

**return**

*fib*(index - 1) +

*fib*(index - 2);

}

}

}

Output of the above code listing would look like:

**Enter an index for the Fibonacci number: 7**

Fibonacci number at index 7 is 13

Fibonacci number at index 7 is 13