Smalltalk Fibonacci

Question

I have to use Smalltalk to return the n^th Fibonacci number, I haven't used this language before. This program returns 1 to any input and I don't know why. It didn't even iterate the for loop I think. Could someone help me? Thanks.

'Which fibonacci number do you want? (n>2)' printNl.
n := stdin nextLine asInteger.

(n <= 2)
    ifTrue: ['Type a larger number, F(1) and F(2) equals 1!' displayNl.]
    ifFalse: [  
        result:= 1.
        parent := 1.
        gparent := 1.   
        2 to: n do: [ :i | [
                result := (parent + gparent).
                gparent := parent.
                parent := result.
                'come on, do something' displayNl.
            ]
        ].
        result displayNl.
    ].

Answer 1

You have an extra set of brackets in your loop body, which makes it create (but not execute) a block on each loop iteration. Here's what you meant to write:

    2 to: n do: [ :i |
        result := (parent + gparent).
        gparent := parent.
        parent := result.
        'come on, do something' displayNl.
    ].