Android Question Decimal problem figures in euros!

[WebQuest]

Hi communities, I'm trying to write a solution that prints decimal places in euros. I can't find a solution that's common to all the numbers. Has anyone had the same problem? any advice is accepted. Thank you

Lprezzo.Text=Prezzo1
    If Lprezzo.Text.Length=3 Or Lprezzo.Text.Length=4 And  Lprezzo.Text.LastIndexOf2(0,4)=0  Then
        If Lprezzo.Text.Length=3 Then
            If Lprezzo.Text.LastIndexOf2(0,3)=0 Or Lprezzo.Text.LastIndexOf2(0,4)=0  Then
                Lprezzo.Text=Prezzo1&".00€"
            Else
                Lprezzo.Text=Prezzo1&"0€"
            End If
        End If
        If Lprezzo.Text.Length=4 Then
            Lprezzo.Text=Prezzo1&"€"
        End If
    Else
        Lprezzo.Text=Prezzo1&".00€"
    End If

The output is this with 5 different digits:
1.00€
10.00€
1000€
1000.00€
10000.00€

 

[Geezer]

I'd take a look at the numberformat or numberformat2 function

 

[Midimaster]

I never use the EUR stored in a FLOAT variable as a base for programming. Better use CENTS instead. So it is better to store 20,60 EUR as 2060 CENTS. This resolves all problem with rounding and displaying money variables.

Dim A as INT = 2060  ' 20,60 EUR
Dim B as INT = 1240  ' 12,40 EUR
Dim C as INT = A+B   ' 33,oo EUR

log ( Money(A) & " " & Money(B)  & " "  & Money(C))


Sub Money(value as INT) as STRING
    dim eur as INT = value/100
    dim cent as INT= Value Mod 100
    Return eur & "." & cent
End Sub

The function converts the values into strings, when needed for printing.

 

[Erel]

Don't try to format the numbers yourself.

Either use NumberFormat(2) or B4XFormatter:

Dim formatter As B4XFormatter
formatter.Initialize
formatter.GetDefaultFormat.MaximumFractions = 2
formatter.GetDefaultFormat.MinimumFractions = 2
formatter.GetDefaultFormat.Postfix = "€"

For Each d As Double In Array(1, 10, 1000, 1.2)
    Log(formatter.Format(d))
Next

 

[emexes]

I'd take a look at the numberformat or numberformat2 function

In particular, the concept of minimum and maximum number of decimal places: sometimes fractions-of-a-cent is reasonable, eg the price of electronic components when costing up a board for production.

 

[emexes]

Better use CENTS instead.

Dim A as INT = 2060  ' 20,60 EUR

Nice solution. I usually use Doubles for accounting, but I appreciate that it freaks some people out.

Note that Int cents max out at 20 million EUR, which ain't worth what it used to be. ✌

 

[LucaMs]

Don't try to format the numbers yourself.

Either use NumberFormat(2) or B4XFormatter:

Dim formatter As B4XFormatter
formatter.Initialize
formatter.GetDefaultFormat.MaximumFractions = 2
formatter.GetDefaultFormat.MinimumFractions = 2
formatter.GetDefaultFormat.Postfix = "€"

For Each d As Double In Array(1, 10, 1000, 1.2)
    Log(formatter.Format(d))
Next

I don't think this works well; probably a bug in B4XFormatData.

The decimal separator on my smartphone (italian language) is comma but B4XFormatData contains dot.

I have an old function (I have to check if I can use JavaObject instead of Reflector) which gets the default decimal separator:

Public Sub getDecimalSeparator As Char
    Dim rfl As Reflector
    Dim nf As Object = rfl.RunStaticMethod("java.text.NumberFormat", "getInstance", Null, Null)
    rfl.Target = nf
    Dim sym As Object = rfl.RunMethod("getDecimalFormatSymbols")
    rfl.Target = sym
    Dim Separator As Char = rfl.RunMethod("getDecimalSeparator")
    Return Separator
End Sub

Running the Erel's code, with few lines added:

Sub Test
    Dim formatter As B4XFormatter
    formatter.Initialize
    formatter.GetDefaultFormat.MaximumFractions = 2
    formatter.GetDefaultFormat.MinimumFractions = 2
    formatter.GetDefaultFormat.Postfix = "€"

    For Each d As Double In Array(1, 10, 1000, 1.2)
        Log(formatter.Format(d))
    Next

    Dim formatData As B4XFormatData = formatter.GetDefaultFormat
    LogColor(formatData, Colors.Blue) 'ignore

    LogColor("DecimalSeparator: " & getDecimalSeparator, Colors.Red)
End Sub

I get:

 

[josejad]

This post could be useful too if you're goint to need locale settings

 

[Sandman]

I never use the EUR stored in a FLOAT variable as a base for programming. Better use CENTS instead. So it is better to store 20,60 EUR as 2060 CENTS. This resolves all problem with rounding and displaying money variables.

While I have never personally worked with financial systems that require any high precision, I have understood that it's common to store the integer part of the money as one INT and the non-integer part as another INT. When used, or presented, they get combined. By storing them as two separate INTs, they never ever gets affected by rounding from the processor etc.

 

[WebQuest]

Amazing I wasn't aware of this type of formatting. erel's solution solved the problem thanks.

 

[emexes]

While I have never personally worked with financial systems that require any high precision, I have understood that it's common to store the integer part of the money as one INT and the non-integer part as another INT.

I have, and I've never seen that. But I imagine it would be fun to roll your own such currency type, especially if the components end up with different signs.

 

[agraham]

For currencies use BigDecimal values

 

[emexes]

For currencies use BigDecimal values

I thought wtf, doesn't Java have a standard Currency type like pretty much every other compiled BASIC, but... heck, you're right.

ps. the is with reference to Java's omission, not to you being right.

 

[agraham]

ps. the is with reference to Java's omission, not to you being right.

Again!