Get number of total decimal places in decimal (including non-significant ones)

Question

If you run this code:

decimal d1 = 0m; 
decimal d2 = 0.0m;
decimal d3 = 0.0000m;

string str1 = d1.ToString(System.Globalization.CultureInfo.InvariantCulture);
string str2 = d2.ToString(System.Globalization.CultureInfo.InvariantCulture);
string str3 = d3.ToString(System.Globalization.CultureInfo.InvariantCulture);

You get :

str1: "0",
str2: "0.0",
str3: "0.0000"

Is there some way in code to get the number of decimal places (as would be output by decimal.ToString above) in the decimal variables ?

i.e. want to get:

d1: 0
d2: 1
d3: 4

(In case anyone is wondering why this is required, it is for some workaround code for a problem involving SSRS and Excel: http://social.technet.microsoft.com/Forums/sqlserver/en-US/5c4fc104-5d69-409d-9a6e-a6354922729a/exporting-ssrs-report-to-excel-2007-excel-found-unreadable-content-in-file-xlsx)

EDIT:

Title has been changed. Sorry for the confusion, guys. In the underlying problem I'm trying to solve, the decimals are always 0 - hence the confusion.

Can you just call `ToString` and count number of digits after `.`? — MarcinJuraszek, Jan 22 '14 at 05:41
@MarcinJuraszek - not a bad idea. I'll use it if there's nothing cleaner. — Moe Sisko, Jan 22 '14 at 05:46
Hope this helps http://stackoverflow.com/questions/13477689/find-number-of-decimal-places-in-decimal-value-regardless-of-culture — V4Vendetta, Jan 22 '14 at 05:47
@V4Vendetta - thanks, burning_LEGION's answer there did the trick. — Moe Sisko, Jan 22 '14 at 05:52

Nitin Varpe · Answer 1 · 2014-01-22T05:55:32.713

2

I think as this is what u need as MarcinJuraszek said

decimal d = 0.0000m;
int count = d.ToString(CultureInfo.InvariantCulture).
            Substring(d.ToString(CultureInfo.InvariantCulture).
            IndexOf(".") + 1).Length;

edited Jan 22 '14 at 05:55

answered Jan 22 '14 at 05:46

Nitin Varpe

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if you don't specify CultureInfo it converts `dot` to `comma.` – Selman Genç Jan 22 '14 at 05:52
@DmitryBychenko actually OP have not defined non-significant decimal places, thats why i thought this will do. OP should have posted example as yours – Nitin Varpe Jan 22 '14 at 06:13

Selman Genç · Answer 2 · 2014-01-22T06:20:46.313

1

decimal d3 = 0.0000m;
bool control = true;
string str = d3.ToString(CultureInfo.InvariantCulture);
int zeroCount = str.Select((c, index) =>
        {
            if (index >  str.IndexOf('.') && c == '0' && control) return 1;

            control = false;
            return 0;
        }).Sum();

edited Jan 22 '14 at 06:20

answered Jan 22 '14 at 05:46

Selman Genç

100,147
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Sorry, but for 0.000100m the soultion(s) should return 3, not 5 – Dmitry Bychenko Jan 22 '14 at 06:09
@DmitryBychenko, you right.I didn't noticed `unsignificant part`.anyway I will change my answer though you are already write the correct method – Selman Genç Jan 22 '14 at 06:12

Dmitry Bychenko · Answer 3 · 2014-01-22T06:22:50.877

Unsignificant digits are those that are between decimal separator and first non-zero digit providing that the number has zero integer part, e.g.:

  0.000     - 3 unsignificant digits
  0.0001    - 3 
  0.000100  - 3 unsignificant digits (not 5!)
  0.12301   - 0
  0.1230    - 0
  0.0123    - 1
  1.0       - 0 unsignificant digits (not 1!)
  1.0000    - 0 unsignificant digits (not 3!)
 -0.0001    - 3

So, the solution can be

public static int UnsignificantDigits(Decimal value) {
  int result = 0;

  String St = value.ToString(CultureInfo.InvariantCulture);

  if (St.StartsWith("0.") || St.StartsWith("-0."))
    for (int i = St.IndexOf('.') + 1; i < St.Length && St[i] == '0'; ++i)
      result += 1;

  return result;
}

...

int count = UnsignificantDigits(0.000m); // <- returns 3

score 0 · Accepted Answer · edited May 23 '17 at 12:03

0

Thanks to @V4Vendetta for pointing me to the other question.

This does the trick:

int count = BitConverter.GetBytes(decimal.GetBits(yourDecimalHere)[3])[2];

(From: https://stackoverflow.com/a/13493771/70140)

edited May 23 '17 at 12:03

Community

1
1

answered Jan 22 '14 at 06:01

Moe Sisko

11,665
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Unfortunatelly, the trick doen't work: for the 0.000100m value the right answer is 3, not 6 – Dmitry Bychenko Jan 22 '14 at 06:12
I did not word my original question very well. I'm actually after the total number of decimal places (including non-significant ones). The trick does what I need. My bad. – Moe Sisko Jan 22 '14 at 06:17

Get number of total decimal places in decimal (including non-significant ones)

4 Answers4