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. Let's create a new codeunit from Object Designer.

2. Then add a global function called Fibonacci that returns an integer with no name.

3. Provide the following parameters for the function:

   Name	Type
   i	Integer

4. Now write the following code to the Fibonacci function:

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

5. Write the following code in the OnRun trigger of the codeunit:

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

6. It's time to save and close the codeunit.

7. On execution of the codeunit, you should see a window similar to 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, and so on.

A recursive function has two parts. The...