I agree completely with David. I make it a habit to have one way in and one way out for my loops and subroutines. It makes it much easier to enhance/debug in the future (which is what most of us spend most of our time doing). I will not say I NEVER break this rule, but it is rare.
John Israel -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of David A. Green Sent: Friday, February 27, 2009 1:25 PM To: [email protected] Subject: RE: [U2] DO/WHILE vs IF THEN George, In my opinion you lose the elegance and readability of the LOOP construct when you use EXIT. Code is easier to debug and enhance when Loops and Subroutines have one entry and one exit. Thanks, David A. Green www.dagconsulting.com (480) 813-1725 -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of George Gallen Sent: Friday, February 27, 2009 9:20 AM To: Ardent Subject: [U2] DO/WHILE vs IF THEN OK Aside from programming styles Is there any "functional" difference between WHILE expression DO and IF NOT(expression) THEN EXIT and UNTIL expression DO and IF expression THEN EXIT First I thought that the DO/WHILE would activate as soon as the condition occurred and drop out of a loop, but that is not the case, the condition has to be active AND control has to be back at the WHILE statement. Example: 0001: CTR=0 0002: LOOP 0003: CTR=CTR+1 0004: WHILE CTR<4 DO 0005: PRINT CTR 0006: CTR=CTR+1 0007: PRINT CTR 0008: CTR=CTR+1 0009: PRINT CTR 0010: CTR=CTR+1 0011: PRINT CTR 0012: CTR=CTR+1 0013: PRINT CTR 0014: CTR=CTR+1 0015: PRINT CTR 0016: CTR=CTR+1 0017: PRINT CTR 0018: REPEAT 0019: STOP 0020: END My first thought was that once CTR = 5, the loop would end (at LINE 12) but it didn't until control was passed back to LINE 4, then it ended. ------- u2-users mailing list [email protected] To unsubscribe please visit http://listserver.u2ug.org/ ------- u2-users mailing list [email protected] To unsubscribe please visit http://listserver.u2ug.org/ ------- u2-users mailing list [email protected] To unsubscribe please visit http://listserver.u2ug.org/
