How does decimal flag works as a parameter in function?

[maniootek 5]

For example, first parameter for function MsgBox() is "flag" which " indicates the type of message box and the possible button combinations." (according to help file)

If I want MsgBox with only "YES" or "NO" button and "QUESTION" icon then I have to pass to flag parameter value "4+32" (36).

Now, how MsgBox know that 36 represents option 4 and option 32? I belive it is mathematic function but don't know which.

I am asking it because I want make my own function with one parameter which could be many of possible combinations.

[czardas 1,200]

It is a binary flag. Bits can be set using BitOr(). You should use BitAnd() to check which bits have been set. For example the number 5 is represented by '0101' in binary. Bits are set in the first and third positions (right to left). The example is demonstrated below.

Local $iFlag = BitOR(1, 4)

MsgBox(0, "Flag", $iFlag)
MsgBox(0, "1", BitAND($iFlag, 1) = 1) ; True - 1st bit is set
MsgBox(0, "2", BitAND($iFlag, 2) = 2) ; False - 2nd bit has not been set
MsgBox(0, "4", BitAND($iFlag, 4) = 4) ; True - 3rd bit is set

See what happens when you change the first line of the code to this:

Local $iFlag = BitOR(1, 4, 5)

Read about Bitwise functions in the help file to find out why it behaves the way it does.
 

Edited February 5, 2018 by czardas