Using recursion

Recursion is not used often in NAV, but the option is available and can shorten your code. Recursion is the process by which a function calls itself.

How to do it...

1. Create a new codeunit from Object Designer.

2. Add a global function, Fibonacci, that returns an integer with no name.

3. The function should take the following parameter:

   Name	Type
   i	Integer

4. Write the following code in your Fibonacci function.

   IF (i <= 2) THEN
   EXIT(1);
   EXIT ( Fibonacci(i-1) + Fibonacci(i-2) );
   

5. Write the following code in your OnRun trigger:

   MESSAGE('Fibonacci(%1) = %2', 4, Fibonacci(4));
   

6. When you run the codeunit you will see a window like the one shown in the following screenshot:

   

How it works...

The Fibonacci sequence is a series of numbers where the value in a certain position is the sum of the number in the previous two positions.

That is: 1, 1, 2, 3, 5, 8, 13, 21, 34, 55...

A recursive function has two parts. The first is a stopping condition. In our Fibonacci function, the stopping condition...