Android Question Float and Double

[Deleted member 103]

Hi,

can anyone tell me why this differential output?

Sub Activity_Create(FirstTime As Boolean)
    'Do not forget to load the layout file created with the visual designer. For example:
    'Activity.LoadLayout("Layout1")

    Dim d As Double
    Dim f As Float
   
    d = 1800 / 1000
    f = 1800 / 1000
   
    Log("d=" & d)
    Log("f=" & f)

End Sub

Log-output:
d=1.8
f=1.7999999523162842

 

[edm68]

See here: https://www.b4x.com/android/forum/threads/problem-with-floats.29345/#post-170283

 

[Deleted member 103]

If so, then the type "float" is not useful for me.
I now exchange all float variables with double.

 

[Erel]

Always use NumberFormat or $1.2 (smart string literal) to convert numbers to strings. Binary floating point numbers cannot accurately represent decimal values.

 

[Deleted member 103]

The function "NumberFormat" does not work with Float.

Sub Activity_Create(FirstTime As Boolean)
    'Do not forget to load the layout file created with the visual designer. For example:
    'Activity.LoadLayout("Layout1")

    Dim d As Double
    Dim f As Float
   
    d = 1800 / 1001
    f = 1800 / 1001
   
    Log("d=" & d)
    Log("f=" & f)
   
    Log(" ")

    d = NumberFormat(d, 1, 4)
    f = NumberFormat(f, 1, 4)

    Log("d=" & d)
    Log("f=" & f)
   
End Sub

Log-output:
d=1.7982017982017982
f=1.7982017993927002

d=1.7982
f=1.798200011253357

 

[Erel]

NumberFormat returns a string.

Log(NumberFormat(f, 1, 4))
Log($"f=$1.4{f}"$)

 

[Deleted member 103]

Unfortunately, I have had too many inaccuracies with the use of float, and so far I do not know where these inaccuracies come from, now it knows.
I will never use Float again in the future.