Question

I am implementing a simple dot product algorithm into actionscript 3.0 codes. Here is the basic example.

(1, 2, 3) • (7, 9, 11) = 1×7 + 2×9 + 3×11 = 58

I have a simple code here.

public var array1:Array = [1, 2, 3]; // 4, 10, 18
    public var array2:Array = [4, 5, 6];
    public var answer:Number = 0;

    public function Algorithm() 
    {
        multiply();
    }
    public function multiply()
    {
        var temp:Number = 0 ;
        while (temp < array1.length) 
        {
            answer = array1[temp] * array2[temp];
            temp++;

        }
        trace(answer += answer);
    }

But when I trace it..instead of 32, it goes 36… looks like it is adding 4 again for the last answer.

Its bugging me.

Answer 1

You are overwriting answer each time the array loops. The only value that is being stored is the last (3*6 = 18). In your trace you are effectively doubling that, giving you 36 every time. Try this:

answer = answer + ( array1[temp] * array2[temp] );

Then just trace answer at the end.