Re: IF statement, I don't understand this

Jack Benny wrote:
This is Unisys A-series C74,
I have
000600 01 SHH-SHIP-CODE PIC 9 VALUE 1.
000700 01 ASM010-I-DIR PIC X VALUE "R".
and
001000 IF SHH-SHIP-CODE = 5 AND ASM010-I-DIR = "L" OR "R" OR "S"
001100 DISPLAY "TRUE"
001200 ELSE
001300 DISPLAY "FALSE".
001400 ENDIF.

It comes up "TRUE" and I don't understand why. It doesn't seem right.

In this case, absent parens, the expression is evaluated pair-wise from left
to right.

SHH-SHIP-CODE = 5 AND ASM010-I-DIR = "L" evaluates as FALSE.

Then you have:

(FALSE) OR ASM010-I-DIR = "R" which evaluates as TRUE

Next you have:
(TRUE) OR ASM010-I-DIR = "S" which evaluates as TRUE

So, the whole expression is TRUE.


.