In all your examples, you support my position. 1 way in, 1 way out. Though to your point, you have clean, concise clean code.
John Israel -----Original Message----- From: owner-u2-us...@listserver.u2ug.org [mailto:owner-u2-us...@listserver.u2ug.org] On Behalf Of MAJ Programming Sent: Friday, February 27, 2009 3:23 PM To: u2-users@listserver.u2ug.org Subject: Re: [U2] DO/WHILE vs IF THEN I should offer a contrary opinion. I support many sets of differently developed code with all my clients. When properly indented, the EXIT is a logical way to conclude the visit in the loop without labeling the REPEAT or introducing other DONE 'style' variables. The code actually shrinks by a few lines. Example: <Before> GOOD.ANS=FALSE LOOP UNTIL GOOD.ANS DO PRINT "ENTER 'Y' OR 'N' ":;INPUT ANS IF ANS="Y" OR ANS="N" THEN GOOD.ANS=TRUE REPEAT <after> LOOP WHILE TRUE DO PRINT "ENTER 'Y' OR 'N' ":;INPUT ANS IF ANS="Y" OR ANS="N" THEN EXIT REPEAT Or my favorite code shrinking syntax: <before> EOF=0 LOOP READNEXT ID ELSE EOF=0 UNTIL EOF DO {process} REPEAT <after> LOOP WHILE READNEXT ID DO {process} REPEAT When I see code that has been heavily flagged I have to scratch my head. EXIT and CONTINUE have been around at least as long as U2 has. I know that they weren't there during the Jurrasic Pick era. My 1 cent, Mark Johnson Maybe I follow poor programmers who got flag-crazy. ----- Original Message ----- From: "David A. Green" <dgr...@dagconsulting.com> To: <u2-users@listserver.u2ug.org> Sent: Friday, February 27, 2009 1:25 PM 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: owner-u2-us...@listserver.u2ug.org > [mailto:owner-u2-us...@listserver.u2ug.org] 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 > u2-users@listserver.u2ug.org > To unsubscribe please visit http://listserver.u2ug.org/ > ------- > u2-users mailing list > u2-users@listserver.u2ug.org > To unsubscribe please visit http://listserver.u2ug.org/ ------- u2-users mailing list u2-users@listserver.u2ug.org To unsubscribe please visit http://listserver.u2ug.org/ ------- u2-users mailing list u2-users@listserver.u2ug.org To unsubscribe please visit http://listserver.u2ug.org/
