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Combobox update a number variable depending on Yes or No selection

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Posted on by CU10041356-0

Hi,

Please can anyone suggest a solution - i am using a Canvas App.

I have a Number Variable :

varBinCalcCheck that is a Global Variable that is set at 0 at App startup.

I have four Comboboxes that are "Yes" or "No" selkections.

cmbQuestionOne

cmbQuestionTwo

cmbQuestionThree

cmbQuestionFour

If ,

cmbQuestionOne.Selected ="Yes" or cmbQuestionOne.Selected = "No" then i want to add 1 to varBinCalcCheck (varBinCalcCheck = varBinCalcCheck +1)

cmbQuestionTwo.Selected ="Yes" or cmbQuestionTwo.Selected = "No" then i want to add 2 to varBinCalcCheck (varBinCalcCheck = varBinCalcCheck +2)

cmbQuestionThree.Selected ="Yes" or cmbQuestionThree.Selected = "No" then i want to add 4 to varBinCalcCheck (varBinCalcCheck = varBinCalcCheck +4)

cmbQuestionFour.Selected ="Yes" or cmbQuestionFour.Selected = "No" then i want to add 8 to varBinCalcCheck (varBinCalcCheck = varBinCalcCheck +8)

cmbQuestionFiveSelected ="Yes" or cmbQuestionFiveSelected = "No" then i want to add 16 to varBinCalcCheck (varBinCalcCheck = varBinCalcCheck +16)

So if all comboboxes were selected as "Yes" then varBinCalcCheck = 31 (also if varBinCalcCheck = 31 then send a simple notification saying "All comboboxes have been answered".)

and if for example,

(if cmbQuestionThree.Selected was not selected as "Yes" or "No" then varBinCalcCheck = 27

If any combobox.Selected is not equal to "Yes" or "No" (so not selected then i would add 0 to varBinCalcCheck

Would this be best put in the "On Change" event?

Assuming i would need to add the whole code for each combobox "On Change" event, rather than individually.

But maybe a better solution for just the fx for the combobox itself on each.

So the code for

cmbQuestionOne fx would only be in the "On Change" event for comboboxOne

cmbQuestionTwo fx would only be in the "On Change" event for comboboxTwo

cmbQuestionThree fx would only be in the "On Change" event for comboboxThree

cmbQuestionFour fx would only be in the "On Change" event for comboboxFour

cmbQuestionFive fx would only be in the "On Change" event for comboboxFive

Any advice greatly appreciated.

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Power Apps Pro Dev & ISV

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Dhanush Pamarthi 8 on at

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Hi,

For this scenario, I would not recommend adding 1, 2, 4, 8, 16 incrementally in each ComboBox OnChange, because the value can easily become incorrect if the user changes an answer more than once.

For example, if the user selects Question 1, then changes it again, the variable could be incremented again and give the wrong total.

The better approach is to recalculate the full value every time any ComboBox changes.

Assuming each ComboBox only allows one selected value and the selected value is either "Yes" or "No", you can use this formula.

Set the same formula in the OnChange property of each ComboBox:

With(

    {

        calcValue:

            If(!IsBlank(cmbQuestionOne.Selected.Value), 1, 0) +

            If(!IsBlank(cmbQuestionTwo.Selected.Value), 2, 0) +

            If(!IsBlank(cmbQuestionThree.Selected.Value), 4, 0) +

            If(!IsBlank(cmbQuestionFour.Selected.Value), 8, 0) +

            If(!IsBlank(cmbQuestionFive.Selected.Value), 16, 0)

    },

    Set(varBinCalcCheck, calcValue);

    If(

        calcValue = 31,

        Notify(

            "All comboboxes have been answered",

            NotificationType.Success

        )

    )

)

This works because:

Question 1 answered = add 1

Question 2 answered = add 2

Question 3 answered = add 4

Question 4 answered = add 8

Question 5 answered = add 16

If all five are answered:

1 + 2 + 4 + 8 + 16 = 31

So varBinCalcCheck = 31 means all ComboBoxes have a value selected.

If this helped solve your issue, please Accept as Solution so others can find it quickly.

If it didn’t fully solve it but was still useful, please click “Yes” on “Was this reply helpful?” or leave a Like :).

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Valantis 6,488 on at

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Hi @CU10041356-0,

Dhanush's approach is exactly right. Recalculating the full value on every OnChange is the correct pattern, never increment/decrement, it breaks on multiple selections.

One addition: instead of placing the same formula in all 5 OnChange properties (which means maintaining it in 5 places), use a named formula or put the calculation in a single reusable expression. The cleanest way in Power Apps is to make varBinCalcCheck a computed label Text property instead of a variable, calculating it directly:

If(!IsBlank(cmbQuestionOne.Selected.Value), 1, 0) +
If(!IsBlank(cmbQuestionTwo.Selected.Value), 2, 0) +
If(!IsBlank(cmbQuestionThree.Selected.Value), 4, 0) +
If(!IsBlank(cmbQuestionFour.Selected.Value), 8, 0) +
If(!IsBlank(cmbQuestionFive.Selected.Value), 16, 0)

This auto-updates whenever any combobox changes, no OnChange code needed at all. Then on your submit button, check if that label's value equals 31 before proceeding. Simpler and no OnChange maintenance.

Best regards,

Valantis

✅ If this helped solve your issue, please Accept as Solution so others can find it quickly.

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🏷️ For follow-ups @Valantis.

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11manish 3,029 on at

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You can use the OnChange event, but rather than incrementing varBinCalcCheck each time a user makes a selection, it's better to recalculate the

total based on the current state of all comboboxes. This avoids issues when users change their answers multiple times.

Set the following formula in the OnChange property of each combobox:

Set( varBinCalcCheck, If(!IsBlank(cmbQuestionOne.Selected), 1, 0) + If(!IsBlank(cmbQuestionTwo.Selected), 2, 0) + If(!IsBlank(cmbQuestionThree.Selected), 4, 0) + If(!IsBlank(cmbQuestionFour.Selected), 8, 0) + If(!IsBlank(cmbQuestionFive.Selected), 16, 0) ); If( varBinCalcCheck = 31, Notify( "All comboboxes have been answered", NotificationType.Success ) )

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