String format gives crash (exited with code 1.)

Bodevinaat

I was trying some different string formats like F2 and D2 on a Double. D2 gives a crash on 26.8.5.

Var Amount As Double = 574748.56
Label1.Text = Amount.ToString("D2")

Error message:

Fatal VM exception: System.FormatException: Format specifier was invalid.
   at System.Number.GetFloatingPointMaxDigitsAndPrecision(Char fmt, Int32& preci
sion, NumberFormatInfo info, Boolean& isSignificantDigits)                                                                                                                                                                                                                                                                                     at System.Number.FormatFloat[TNumber,TChar](ValueListBuilder`1& vlb, TNumber
value, ReadOnlySpan`1 format, NumberFormatInfo info)                                                                                                                                                                                                                                                                                           at System.Number.FormatFloat[TNumber](TNumber value, String format, NumberFor
matInfo info)                                                                                                                                                                                                                                                                                                                                  at Objo.StdLib.DoubleMethods.<>c.<Register>b__0_6(VM _, ReadOnlySpan`1 args)
   at Objo.VM.VM.Run(Int32 exitAtFp)
   at Objo.VM.VM.InvokeMethod(ObjoClosure method, Value receiver, Value[] args,
Boolean allowWhileStopRequested)                                                                                                                                                                                                                                                                                                               at Objo.StdLib.Desktop.ControlMethods.CallControlEventHandler(VM vm, ObjoInst
ance eventSource, Value handler, Value[] args)                                                                                                                                                                                                                                                                                                 at Objo.StdLib.Desktop.ControlMethods.FireEvent(VM vm, ObjoInstance instance,
 String declaringTypeName, String eventName)

ps lots of white space in the text due to strange formatting in error pane

Garry

Thanks for reporting this.

D2 is an integer format, so it isn’t valid for a Double. To display two decimal places, use:

Var amount As Double = 574748.56
Label1.Text = amount.ToString("F2")

If you need a predictable decimal point regardless of the user’s locale, use:

Label1.Text = amount.ToString("F2", Locale.Invariant)

The fatal crash was nevertheless an Objo bug. An invalid format string should raise a normal runtime exception, not allow a .NET FormatException to escape and terminate the application.

This has been fixed for the next release: https://feedback.objo.dev/bug/1263

Invalid format strings passed to Double, Integer, Currency, or DateTime formatting methods now raise a catchable InvalidArgumentException with a useful message and the correct Objo source location.