Reg CHECK command

Question

Dear guys,
I have piece of code below.
MODULE 9201_PAI_SET_PSTYV INPUT.
CHECK SY-UCOMM <> 'PRINT'
     OR SY-UCOMM <> 'CLEAR' OR SY-UCOMM <> 'CLEAR2'.
  CHECK ZSDORDER-MATNR <> SPACE AND ZSDORDER-CHECK = SPACE.
  DATA:
    W_MATNR LIKE ZSDORDER-MATNR.                 
  IF G_PSTYV <> SPACE.                    READ TABLE GTAB_DORDER INDEX SY-STEPL.
    ZSDORDER-PSTYV = GTAB_DORDER-PSTYV.
    IF SY-STEPL = SY-TFILL.
      CLEAR G_PSTYV.
    ENDIF.
  ELSE.
ENDMODULE.
Qn:
I Could not understand what mean by CHECK statement( CHECK SY-UCOMM <> 'PRINT') here..
Is this same as IF statement?
Suggestion please..
Ambichan

Answer 1

Hi Ambi Chan,
The main difference between a CHECK and an IF statement is that a CHECK statement stops the processing of all the subsequent line within a processing block, if the condition is negative. IF statement will stop the processing of the lines that are enclosed within the IF ENDIF block.
PERFORM CHECK_TEXT.
WRITE 'ABC'.
FORM CHECK_TEXT.
  CHECK V_TEXT = 'ABC'.
  WRITE V_TEXT.
  L_TEXT = V_TEXT.
ENDFORM.
In the above code, both the 'WRITE V_TEXT.' and the 'L_TEXT = V_TEXT.' statement will not be executed if V_TEXT is not equal to 'ABC' and the processing continues after the PERFORM statement. Compare the same with an IF statement.
PERFORM CHECK_TEXT.
WRITE 'ABC'.
FORM CHECK_TEXT.
  IF V_TEXT = 'ABC'.
    WRITE V_TEXT.
  ENDIF.
  L_TEXT = V_TEXT.
ENDFORM.
Here if V_TEXT is not ABC, then the 'WRITE V_TEXT' will not be executed, but the 'L_TEXT = V_TEXT' will be executed.
Hope this helps,
Srinivas