Odd or even numbers

pavpav

Hi

I would like to check if a value is odd or even, does anyone have a good solution for this in RAPID?

I know its possible to divide a value by 2 and count the amount of decimals, but i cannot find a function that can count decimals.

Thank you

blind3rr

   
    FUNC num OddEven(num x)
        VAR num nAux;
        
        nAux := Trunc(x) MOD 2;
        TEST nAux
        CASE 0:
            ! Value is even
            RETURN 2;
        CASE 1:
            ! Value is odd
            RETURN 1;
        ENDTEST
    ENDFUNC

Something like this?
    

pavpav

Thx

I read about MOD and the way i see it is that it counts the amount of numbers a value consists of?

11/5 is 2,2 so MOD will be 2 because there is two numbers?

B_Baan

You clearly don't understand MOD yet, but you know it's function.

This page contains an explanation of the mathematics behind the MOD (A.K.A. Modulo) instruction:

http://en.wikipedia.org/wiki/Modulo_operation

Hope this helps

pavpav

Ah thx the remainder after a quotient

Kristo

One way is to check first bit of the number. If the bit is 1 than the number is odd, if it's 0, the number is even. Example code:


!I converted the num to dnum, than it's possible to check higher value number than 0...255.

FUNC bool checkIsNumberOddOrNot(num inputNum)

       VAR dnum inputDnum;

       

       inputDnum:=numToDnum(inputNum);

       

       IF BitCheckDnum(inputDnum, 1) = TRUE THEN

           !first bit is true, it's an odd number

           RETURN TRUE;

       ELSE

           !first bit is false, it's not an odd number

           RETURN FALSE;

       ENDIF

   ENDFUNC



Br,
Kristo