The operation yail-divide cannot accept the arguments [''], [100]

Can someone help? I'm not an experienced coder but we use this app to learn and code (in a way), and I'm doing this bmi calculator for a project.... I need to fix this very soon

Screenshot 2025-10-20 233613




Screenshot 2025-10-20 235535

you are using the divide block and the first element is an empty string
unknown

here are you using the divide block
unknown2

one solution is to set height_input to 0 in the Designer
or do some data validation before doing any calculation, i.e. check if height_input is not empty

Taifun

Im sorry im stupid, but i dont think I understand what you mean. How do I check if my height_input is empty, because I can remember when the app still worked even if the: height_input.Text/100; was still there. Now it doesn't. Im sorry I just need clarification since i am new to this app but I am very much willing to learn.

If is empty height_input Text
Then "please enter a height"
Else do the calculation

You can find the is empty block in the text drawer

A very good way to learn App Inventor is to read the free Inventor's Manual here in the AI2 free online eBook App Inventor 2 Book: Create Your Own Android Apps ... the links are at the bottom of the Web page. The book 'teaches' users how to program with AI2 blocks.
There is a free programming course here Course In A Box and the aia files for the projects in the book are here: App Inventor 2 Book: Create Your Own Android Apps
How to do a lot of basic things with App Inventor are described here: How do you...? .

Also do the tutorials Our Tutorials! to learn the basics of App Inventor, then try something and follow the Top 5 Tips: How to learn App Inventor

Taifun


Trying to push the limits! Snippets, Tutorials and Extensions from Pura Vida Apps by icon24 Taifun.

1 Like