powerpoint, vba, generate a random number from a specific set - vba

Question

VBA - how can i generate a random number within the specific set 3,5,7,9,11,13.
these numbers represent slide numbers (destinations) which the user will be taken to when a button is clicked.

Answer 1

Edit: Modified to include a more comprehensive solution at request of OP
Objective: Randomly select one of six possible slide numbers to display following the click of a button.
Step 1: Code to randomize slide number selection
Map the target values into an array. Note the number of elements in the resultant array - in this case, 6. Generate a random integer from 1 to 6, and use that value as an index into the array, returning the value at that index position.
Something like the following (untested)
function randomSlideNumber() as Integer
Dim index
Dim targetValues(1 to 6) as Integer
targetValues(1) = 3
targetValues(2) = 5
targetValues(3) = 7
targetValues(4) = 9
targetValues(5) = 11
targetValues(6) = 13
index = Int(6 * Rnd + 1)
randomSlideNumber = targetValues(index)
end function
Step 2: Add slides to a Powerpoint presentation up to the number desired in the random selector
I'm assuming the OP already has at least 13 slides in his presentation :)
Step 3: Add an additional slide to the presentation, and add a CommandButton to it
With the new slide active in Powerpoint, click the 'Developer' tab.
Select a CommandButton from the Controls toolbar, and draw it onto the new slide.
Double-click the CommandButton. This should open the VBA editor with a stub Click event handler for the CommandButton, called CommandButton1_Click().
Modify the handler code as follows:
P
Private Sub CommandButton1_Click()
SlideShowWindows(1).View.GotoSlide randomSlideNumber
End Sub
Step 5: Start the slide show, using the slide with the new CommandButton as the starting point
With the new slide active, select the "Slide Show" tab from the ribbon bar
Click "From Current Slide" from the "Start Slide Show" bar.
Step 6: Click the CommandButton on the slide, and verify that the active slide changes to one of those returned by the randomSlideNumber() function
Voila! :)
Code Discussion
Note: This involves a little detail about the PowerPoint VBA object model.
Clicking the CommandButton in the slide created in Step 3 fires the CommandButtton1_Click() event handler created in Step 4. The event handler then goes to the current View of the first SlideShowWindow object SlideShowWindow(1).View, and calls the GotoSlide method of the View. The GotoSlide method expects a slide number as a parameter, which is provided by the call to the 'randomSlideNumber' function defined earlier. That function should return one of 3, 5, 7, 9, 11, or 13.
That should do the trick.
Caveats: There is obviously no error handling in this code; its addition is left as an exercise. Further, this has not been extensively tested against the very latest version of Powerpoint, but did work in the test shell I created.