How to include decimal point to string in vb.net?

Question

How to add decimal point (with two decimal places) to string, without converting string to decimal?

For example (Dim str1 as String), regardless str1 has value: 100 , 100.0 , 100.00, or 100.5 , 100.50... I'd like to get the output: 100.00 or 100.50, with two decimal places.

`CDec(myString).ToString("D2")` isn't so prohibitive that you should balk at it. Just cast and call `ToString`. — lsuarez, Jan 17 '12 at 13:21
don't know vb but in c# convert it to decimal, round it up and then convert back to string http://stackoverflow.com/questions/257005/how-do-you-round-a-number-to-two-decimal-places-in-c — dierre, Jan 17 '12 at 13:23
I have tried with `CDec(myString).ToString("D2")`, but I got Exception error: ex.Message = "Format specifier was invalid." This is my code: `Dim str1 As String = "100.0"` `Dim str2 As String` `str2 = CDec(str1).ToString("D2")` — Mega, Jan 17 '12 at 13:34

Olivier Jacot-Descombes · Accepted Answer · 2012-01-17T13:33:06.337

Public Function FormatNumber(ByVal s As String) As String
    Dim pos As Integer = s.IndexOf("."c)
    If pos = -1 Then ' No decimal point
        Return s & ".00"
    Else
        Return (s & "00").Substring(0, pos + 3)
    End If
End Function

And since you inserted a C# tag:

public string FormatNumber(string s)
{
    int pos = s.IndexOf('.');
    if (pos == -1) { // No decimal point 
        return s + ".00";
    } else {
        return (s + "00").Substring(0, pos + 3);
    }
}

However, note that superfluous decimals will be truncated - no rounding occurs!

score 0 · Answer 2 · answered Jan 17 '12 at 13:27

Can't add comment yet, so excuse the additional post...

lthibodeaux and dierre are correct. Converting to decimal and back is much better. Otherwise you could create a function that looks for a decimal point in the string and then appends zeroes to it based on where it finds it. The problem is if you get a str like "13.876". You would have to figure out how to do rounding on the string.

Go the easy route.

score 0 · Answer 3 · answered Jan 17 '12 at 13:29

Public Shared Function TwoDecimalString(input As String) As String
    Dim output As String
    Dim splittedInput As String() = input.Split("."C)
    If splittedInput.Length = 1 Then
        output = input & ".00"
    Else
        output = splittedInput(0) & "." & splittedInput(1).PadRight(2, "0"C)
    End If
    Return output
End Function

How to include decimal point to string in vb.net?

3 Answers3