App Designer- How to make button display answers in different numeric fields depending on the clicks

Hello, Im currently designing a game in App designer where you can click a button and it displays a random number between 1-10. Currently in my app, when you click the "roll" button it generates 4 different numbers into 4 different text fields and I don't want that. I want the button when clicked once it displays one random generated number in the first text box and when I click roll again it displays another number in the second box and etc... for the next two clicks. Heres an example of my code below:

function RollValueChanged(app, event)    %Roll is the name of the button 
        

FirstValue= randi([1, 10],1,1);
  app.FirstText.Value= FirstValue;    %FirstText is the numeric field text box that the answer will be shown at. 
  
  
        

SecondValue= randi([1, 10],1,1);
 app.SecondText.Value= SecondValue;  %SecondText is the numeric field text box that the answer will be shown at. 
  
  
  
ThirdValue= randi([1, 10],1,1);
 app.ThirdText.Value= ThirdValue;  %ThirdText is the numeric field text box that the answer will be shown at. 
  

 FourthValue= randi([1, 10],1,1);
  app.FourthText.Value= FourthValue;    %FourthText is the numeric field text box that the answer will be shown at. 

[Mohammad Sami]

what happens to the first value, when you click second time?

what happens when you click the fifth time ?

[Sean]

The first value and the rest of the values will be replaced with a whole new set of randomized numbers. Each click will keep randomizing all the values. For example in the picture below, when I click the button for the first time it gives me 1,2,6,4 and when I click roll again it will give me 1,1,3,3. I want it where when I click roll for the first time gives a number in bottom box, and when I click it again it gives another number in the 2nd box from the bottom and etc...

[Mohammad Sami]

I meant what you want to happen to the first value when you click the second time. So for the second time onwards, do you want to keep the values generated previously ? What should happen when you click the 5th time ?

[Sean]

I want the first value to remain the same and yeah after the second time onwards it keeps the previously generated number. Also when you click the button 5 or times nothing will happen. You can only click four times to generate the four numbers.

Answer 1

[Mohammad Sami]

Something like this should work. it assumes the initial values are set to 0.

function RollValueChanged(app, event)    %Roll is the name of the button         
Value= randi([1, 10],1,1);
switch true
    case app.FirstText.Value == 0
        app.FirstText.Value = Value;
    case app.SecondText.Value == 0
        app.SecondText.Value = Value;
    case app.ThirdText.Value == 0
        app.ThirdText.Value = Value;
    case app.FourthText.Value == 0
        app.FourthText.Value = Value;
    otherwise
        % do nothing
end
end

[Sean]

Can you explain why we would use a switch here and why set the switch to true? The function works, but I don't understand why it works. Thank you in advance!

[Mohammad Sami]

It's not necessary to do it this way. You can essentially do the same with if else statements.

The switch statement will evaluate the case statements and it will execute the one that is true. If there are multiple cases that are true, it will only execute the first one that is true.

There is some discussion on this topic on the thread here. You can see if you want to implement this with if else.

https://www.mathworks.com/matlabcentral/answers/12290-problem-using-switch-with-logical-operators-larger-than-do-this-or-less-than-do-this

There are still other ways to implement this besides the above 2.