Need help this with this massage "The operation format as decimal cannot accept the arguments: , [""], [2]"

MIT App Inventor Help
1

The operation format as decimal cannot accept the arguments: , [""], [2]

This is the message I get and the blocks I built, is there anyone who can help me with this message I would love help

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2

Check that the textboxes (VOLT, CURRENT...) you are using in blocks "format as decimal numbers" are not empty. The error indicates that one is empty.

3

when i enter a new number or delete the number that was there i get that massage

4

When you change the text the event TextChanged is triggered so, if you have cleared the textBox, then it will try to do the operation...with the empty textBox...place an if statemet, to ensure you only execute the operations if the involved textBoxes are not empty.
You can also check the input is a number. A basic example:

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1 Like
5

thanks it works

6

I find an Enter Button works better for initiating calculations than text changed events.

Text Changed is over eager.

(I would call this disorder Premature Evaluation)