The recursive fibonacci function:
INPUT "Gimme a number!"; number%
PRINT "Fibonacci function of that number is"; fib%(number%)
SYSTEM
FUNCTION fib%(number AS INTEGER)
'No error checking (IE: negative number will be the same as 0)
IF number > 1 THEN fib% = fib%(number - 2) + fib%(number - 1): EXIT FUNCTION
IF number = 1 THEN fib% = 1: EXIT FUNCTION
fib% = 1
END FUNCTION
The iterative fibonacci function:
n = 10
fib = 0
1 IF n <> 0 THEN fib = fib + n: n = n - 1: GOTO 1
PRINT fib
Credit: Agamemnus