Modulo on a big number

lightning

Hi,

I need to perform a modulo operation on a very big number (30 digits, could even be all 9's), is it even possible to do that in Navision?
If so, how would i do that? It would be a simple VARIABLE MOD 97 operation.

Also, the 'number' is stored in a Text variable, since obviously integer can't hold a number of this magnitude

Slawek_Guzek

Nope. Such a large number cannot be represented on a regular PC.

'Standard' arithmetic is limited to 64bits which is about 16 digits in case of double precision decimal, or 19 digits for big integer.

Maybe some specialistic math software can handle it, NAV is not an exampe of one...

Duikmeester

OBJECT Codeunit 50000 BigInteger
{
  OBJECT-PROPERTIES
  {
    Date=;
    Time=;
    Version List=;
  }
  PROPERTIES
  {
    OnRun=VAR
            BigInteger@50000 : DotNet "'System.Numerics, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'.System.Numerics.BigInteger";
            aResult@50001 : Text;
            aInteger@50002 : Integer;
          BEGIN
            aResult := BigInteger.Remainder(BigInteger.Parse('999999999999999999999999999999'),BigInteger.Parse('97')).ToString();
            EVALUATE(aInteger,aResult);
            MESSAGE('%1',aInteger); //84
          END;

  }
  CODE
  {

    BEGIN
    END.
  }
}

Edit: Oh, classic forum... Then it works only when using the 2009 RTC.

lightning

Found a way, here's the code:

WHILE STRLEN(CheckSumCalculator) > 6 DO
  CheckSumCalculator := CalculateModulus(COPYSTR(CheckSumCalculator,1,6), 97) + COPYSTR(CheckSumCalculator, 7)
EVALUATE(ToInt, CheckSumCalculator);
ToInt := ToInt MOD 97;

And the CalculateModulus procedure

EVALUATE(I,Number);
I := I MOD Modulus;
IF I = 0 THEN
  EXIT('');
EXIT(FORMAT(I));

I took the solution from "CheckIBAN" from NAV2017

Slawek_Guzek

@Duikmeester
Even in 3Tier - are you sure the results are correct?

aResult := BigInteger.Remainder(
  BigInteger.Parse('979999990000000000000000000000'), BigInteger.Parse('97')).ToString();

aResult2 := BigInteger.Remainder(
  BigInteger.Parse('979999990000000000000000000001'), BigInteger.Parse('97')).ToString();
EVALUATE(aInteger2,aResult2);

MESSAGE('%1, %2',aInteger, aInteger2); //0, 69

Duikmeester

@Slawek_Guzek you forgot a line:

EVALUATE(aInteger,aResult);

Slawek_Guzek