# Recursion

Recursive programming is a procedure in which a method calls itself, so that a problem is solved more and more with each method call. This continues until the problem is reduced to a very simple case.

Some tasks in computer science can be solved well by reducing a large problem step by step to smaller and smaller problems of the same kind until simple (trivial) solutions arise . From this finally the solution of the original large problem is put together.

## Syntax

``````modifiers return_type method_name(type parameter) {
// code to be executed
return method_name(type parameter)
}``````

## Example: factorial

``````public class FactorialRecursion {
public static int factorial(int number) {
if (number < 2) {
return 1;
} else {
return number * factorial(number - 1);
}
}

public static void main(String[] args) {
int factorial = factorial(8);

System.out.println("factorial of 8 is " + factorial);
}
}``````
##### Output
``factorial of 8 is 40320``

## Example: fibonacci

``````public class FibonacciRecursion {
public static int fibonacciAlgorithm(int number) {
if (number == 0 || number == 1) {
return number;
} else {
return fibonacciAlgorithm(number - 1) + fibonacciAlgorithm(number - 2);
}
}

public static void main(String[] args) {
int fib = fibonacciAlgorithm(10);

System.out.println("fibonacci number of the number 10 is " + fib);
}
}``````
##### Output
``fibonacci number of the number 10 is 55``