Bug? Bugs in B4A V 10

[Marcos Alves]

Hello all,

Yesterday I upgraded the version of my B4A from 9.80 to 10.0. Just after the upgrade I noticed that some maps aren't showed anymore in a debug break point when I put the mouse cursor over the variable (which is bad because causes some difficulty to debug ).
But today I noticed a very bad error: in a app that was working fine some lists elements were duplicated. Debugging I discovered that a comparison test to check if the respective line is multiple of 20 (when and alert line should be showed) isn't working anymore.
In this test I get the line number and store it in an int variable, comparing with the original value. Something like this:

    Dim intLine as int
    Dim lineMod as as double
    for i = 0 to maxLines
        intLine = i/20
        lineMod  = i /20
        if lineMod = intLine then
           ... <- here the code to show the line each 20 lines
        end if
    next

The code above, in B4A v.10, is returning true in the test even when intLine is 0 and lineMod is 0.05 (which is wrong and in different from the behavior of the previous versions). This looks like a bug (together with the problems of maps showing in debug mode).
Please, does anybody is having the same problems?

Thanks!

 

[Pendrush]

You compare integer and double are they equal?

Dim a As Int = 1
Dim b As Double = 1.9
If a = b Then
   Log("equal")
Else
   Log ("not equal")
End If

this will print in log "equal".
If you want this to work as expected, you need to compare same type, int with int or double with double.

 

[Marcos Alves]

You compare integer and double are they equal?

Dim a As Int = 1
Dim b As Double = 1.9
If a = b Then
   Log("equal")
Else
   Log ("not equal")
End If

this will print in log EQUAL

Yes ! This is clearly wrong no ?

 

[Star-Dust]

Yes ! This is clearly wrong no ?

try this

Dim a As Int = 1
Dim b As Double = 1.9
If b = a Then
   Log("equal")
Else
   Log ("not equal")
End If

this will print in log NOT EQUAL

 

[Pendrush]

If you want this to work as expected, you need to compare same type, int with int or double with double.

 

[Pendrush]

try this

Dim a As Int = 1
Dim b As Double = 1.9
If b = a Then
   Log("equal")
Else
   Log ("not equal")
End If

this will print in log NOT EQUAL

Test the code please

EDIT: oh.. I did not see that you have replaced side

 

[Star-Dust]

See this

B4J v8.30 BETA is available for download

Improvements: Support for Java 14. As with Java 11, B4J expects a specific structure. You should download this package (OpenJDK 14 + OpenJFX 14): https://b4xfiles-4c17.kxcdn.com/jdk-14.0.1.zip Build standalone package - B4JPackager11 is now integrated in the IDE. This makes it simpler to build...

www.b4x.com

 

[Star-Dust]

B4A 9.90 New warning:
"Comparison of Object to other types will fail if exact types do not match.
Better to put the object on the right side of the comparison. (warning #35)"
See this post for more information: https://www.b4x.com/android/forum/t...-is-available-for-download.117877/post-737515.

B4A v9.90 BETA is available for download

I'm happy to release a new update. Improvements: Add new module - Option to add the new module to the parent folder. This is useful in cross platform projects where the modules are shared between the different platforms. Fix for a design issue that existed since B4A v1.0 where in some cases...

www.b4x.com

This happen that with the new versions, the first variable in comparison is the one that determines the type of comparison.

If the former is int the latter will be casteded int

 

[Marcos Alves]

No... I always use this kind of comparison to know if a number is divisible by other.
1. Create an int as variable (r1)
2. Create a double. (r2)

put the same division result in both... (example: a/b). If r1 is equal to r2, then a is divisible by b. Else, it isn't . (r1 = a/b has the same effect of legacy code in Visual Studio MS platform - Legacy Visual Basic... - r2 = int(a/b) )
And the most important: this WAS working in the previous B4A version (I checked - I was using 9.30 and upgraded to 10 yesterday)

 

[Marcos Alves]

B4A 9.90 New warning:
"Comparison of Object to other types will fail if exact types do not match.
Better to put the object on the right side of the comparison. (warning #35)"
See this post for more information: https://www.b4x.com/android/forum/t...-is-available-for-download.117877/post-737515.

B4A v9.90 BETA is available for download

I'm happy to release a new update. Improvements: Add new module - Option to add the new module to the parent folder. This is useful in cross platform projects where the modules are shared between the different platforms. Fix for a design issue that existed since B4A v1.0 where in some cases...

www.b4x.com

This happen that with the new versions, the first variable in comparison is the one that determines the type of comparison.

If the former is int the latter will be casteded int

Which means that I need to swap the order of the variables in the comparison right?

 

[Star-Dust]

No... I always use this kind of comparison to know if a number is divisible by other.
1. Create an int as variable (r1)
2. Create a double. (r2)

put the same division result in both... (example: a/b). If r1 is equal to r2, then a is divisible by b. Else, it isn't . (r1 = a/b has the same effect of legacy code in Visual Studio MS platform - Legacy Visual Basic... - r2 = int(a/b) )
And the most important: this WAS working in the previous B4A version (I checked - I was using 9.30 and upgraded to 10 yesterday)

Sorry I did not understand, fas an example of what you mean

 

[Star-Dust]

Which means that I need to swap the order of the variables in the comparison right?

With the code you posted, it really means swapping places

 

[Marcos Alves]

try this

This isn't really usual and even strange! The order of the comparison factors shouldn't change the result. This kind of behavior could break many codes came from previous versions!

 

[Marcos Alves]

With the code you posted, it really means swapping places

Ok, I only swapped the order of the factors in if and worked. I know many languages and in my 30 years of programming I never saw this behavior. For me it's a bug.

 

[Marcos Alves]

Sorry I did not understand, fas an example of what you mean

Objective: discover if a number is divisible by other:

Approach 1: use the "int" command (which doesn't exist in B4A): ex: if (a/b) = int(a/b) then log('OK')

Approach 2: store the result in a int variable and compare:
Dim r as int = (a/b)
if r = (a/b) then log('OK')

that's what I mean. ?

 

[Alex_197]

Objective: discover if a number is divisible by other:

Approach 1: use the "int" command (which doesn't exists in B4A): ex: if (a/b) = int(a/b) then log('OK')

Approach 2: store the result in a int variable and compare:
Dim r as int = (a/b)
if r = (a/b) then log('OK')

that's what I mean. ?

Why not use mod?

If aDouble mod bInt = 0 then
else
end if

 

[Marcos Alves]

Why not use mod?

If aDouble mod bInt = 0 then
else
end if

Habit . I'm a veteran (30 years programming)

 

[Pendrush]

As you can see, this is not posible in Android Studio you can also see error explanation.
Erel make it to work in B4x, but comparing different type is not posible in any other language that I know.

 

[Alex_197]

Habit . I'm a veteran (30 years programming)

So do I. My first code was written in 1987 in Fortran.

 

[Marcos Alves]

As you can see, this is not posible in Android Studio you can also see error explanation.
Erel make it to work in B4x, but comparing different type is not posible in any other language that I know.

View attachment 97236

In php you can compare different types. In legacy VB from MS Visual Studio (in which it's supposed to be based B4A either). In Pascal and Fortran its possible also. In the "died" C Builder from Borland it's possible also.