Android Question Exception: Cannot parse: -1 as boolean

[foretek]

My project use Bluetooth. I port a working code from VB to B4A. When data in Bluetooth communication, I received "Exception: Cannot parse: -1 as boolean" error at (java line 1501). Total code has 1109 line in B4A. Here is the message. Any help? Thank you.

 

[drgottjr]

it is not unusual to incorrectly use the result of an operation as a boolean.
as an example, a string compare returns an integer, not true/false.

this code will throw the error you see:

if name.compareTo("foretek") then     ' <<<< compareTo() returns an int, not a boolean
   log("hello, " & name)
else
   log("you are not foretek")
end if

in this example, the correct syntax is: if name.compareTo("foretek") = 0 then...

see if any operations that you are using to determine true or false actually return an integer.
there is a hint in the error message: your sub rxprocess

 

[foretek]

Thanks for replying. I only have one Sub that uses Boolean as return. I changed its return as Int, returns 0, or 1. Also changed its calling routine. That part works fine. I still get the "Cannot parse: -1 as boolean" error. Is there any way I can look into java line 1501 to find out which B4A statement causes this?

 

[DonManfred]

Is there any way I can look into java line 1501 to find out which B4A statement causes this?

sure. look at the generated java sources. Objects\src\*.* (search for the main.java)

 

[klaus]

Couldn't you test your program in Debug mode? Then the compiler will stop at the code line with the error.

 

[foretek]

Hi, Klaus. I am new. Your suggestion is what I need. I found the problem. I use a received byte from bluetooth to assign to a checkbox1.Checked to turn it on/off with value 255 or 0. The received byte value 255 becomes -1 in B4A. When -1 is assigned to checkbox1.Checked, it generate the "Cannot parse: -1 as boolean" error. Thanks for all your helps.

 

[klaus]

Maybe a routine like this could help to convert:

Sub IntToBoolean(Value As Int) As Boolean
    If Value = 0 Then
        Return False
    Else
        Return True
    End If
End Sub

 

[foretek]

Thank you, klaus, That solves the problem.