How to limit the number of responses for a multiple-choices question

[vchung]

I want to limit the number of answers selection for a multiple choices question (3 responses as maximum for that question), and I inserted the syntax: “(if(count-selected(.)>2,true())” under settings of that question in the web-form, but the system displayed an error message when I clicked to preview or deploy it. Anyone could you please help me to check and fix this issue?
Thank you very much!

[wroos]

Welcome @vchung,
You are missing the else case in your if clause.

Often you can get help directly by using the search function of this forum, e.g.
https://community.kobotoolbox.org/search?q=limit%20response%20number%20multiple

Often also the Help Center articles provide answers.

@Kal_Lam. A count-selected example might be good to.add in the Help Center, please. (I found nothing there.)

[Kal_Lam]

Well noted @wroos! We will keep this on our radar.

[Kal_Lam]

@vchung, I see that your if statement is not complete. It should have 3 arguments. Maybe you should be able to learn more about the same through this post discussed previously:

When is if() function used in formbuilding?

You could use the if() statement when you have to assign a certain value/expression for a certain condition else use another value/expression. Thus, the if statements require three arguments: a condition; the result if the condition is true; and the result if the condition is false. The syntax would be as follows: if(condtion,value,value) if(condtion,expression,expression) if(condtion,value,expression) if(condtion,expression,value) You could learn more about the if-statement by following o…

[vchung]

THanks so much!

[Angelu]

Thanks for sharing this info this is useful keep it up.