An improved FOR NEXT loop

[bplus]

It's so basic....

'Dont forget that the for/next command stops when x becomes > ITERATION

START = 0
ITERATION = 10
County = 0

For x = START To ITERATION
    County = County + 1
Next x
Print "County="; County; " and X="; x; "    Calculated steps for next here is :"; (ITERATION - START + 1); ""

+1

@NOVARSEG you can use a While... Wend loop structure if you want that kind of loop counter index plus it's a faster loop structure.

[FellippeHeitor]

Cobalt is a purist.

[bplus]

Cobalt is a purist.

I can definitely respect that :)

[Cobalt]

Cobalt is a purist.

@FellippeHeitor Darn Straight, and Proud of it.

Not a single GOSUB let alone a GOTO must be talk'n from Cobalt Code World again.

If you are dissing EXIT DO again that saves us from spaghetti code, at least in bplus Code World ;-))

EXIT loop is an elegant way out of a loop. I don't think that's just my opinion, I think the majority of people who complained of spaghetti code would agree that it sure beats a GOTO out of loop.

@bplus : AS a Purist, any command that causes the the code to jump out of line is spaghetti code. And there is never a need for it.
Unless we were programing in assembler which would leave no choice. But BASIC is a high enough programing language we can completely avoid it in our code.

Code: QB64: [Select]

1. DIM A AS _UNSIGNED _BYTE
2. CONST TRUE = -1, FALSE = NOT TRUE
3. A = 255
4. DIM B AS _UNSIGNED _BYTE
5.  
6. B = 0
7. DO
8.  
9.     PRINT "hi"
10.     B = B + 1
11.     IF B > A THEN Flag%% = TRUE 'Will never happen because the B is an incorrect variable type here.
12.  
13.     IF INKEY$ = CHR$(27) THEN Flag%% = TRUE
14.  
15. LOOP UNTIL Flag%%
16. PRINT B
17. END
18.  

See we do not need any GOSUB, GOTO, or EXITs here.

@Cobalt
 I made some mistakes in the code but corrected them.  FOR NEXT loops work well enough.   FOR NEXT loops must have been coded 50 years ago and they work fine but the counter variable, after exit,  is always one more than the limit (or 0 in the case of a wrap around) and it does not have to be that way.

I can't think of any good reason for it.

@NOVARSEG
The FOR\NEXT is a loop that happens while a certain variable is between 2 points(including those points). So to leave that loop the value has to be outside those points.

Code: QB64: [Select]

1. MIN = 0 'FOR B = 0
2. MAX = 10  'TO 10
3. B = MIN
4. DO
5.  B = B + 1 'STEP 1
6. LOOP WHILE  B <= MAX 'NEXT B

[George McGinn]

@bplus I disagree in part. I try to stick to modular design, and mostly a purist too, and I will use a GOTO to skip a block of code within a function or module, or to save on repeating a block of code in many IF or CASE statements. That is usually the only exception that I believe does not violate the the modular coding construct. I do this if I want to execute an endPROG: label that does some housekeeping before ending a program, rather than placing the END statement everywhere I want to end a program, or duplicating my housekeeping code many times. If more than my main logic needs to execute the endPROG, then I do make it a FUNCTION.

I use this when an IF/THEN/ELSE or CASE does not work. In other words, I may want that code executed, regardless of a tested condition, or I may want to bypass it. Rather than coding that block of code in my IF statement and again outside of it (makes for maintenance headaches) I will use a GOTO. This saves on coding when you need to replicate that code in many IF statements.

Otherwise, a program without structure with many GOTO's is spaghetti code, which I do agree with bplus. GOTO's should be used judiciously.

@bplus : AS a Purist, any command that causes the the code to jump out of line is spaghetti code. And there is never a need for it.
Unless we were programing in assembler which would leave no choice. But BASIC is a high enough programing language we can completely avoid it in our code.

[SMcNeill]

OK so this is the action of the usual FOR NEXT loop

notice that things go wrong when B is a _UNSIGNED _BYTE

B has a value of 255 and then is incremented and so now equals zero. The FOR NEXT goes into an endless loop but as we know that does not happen - confused?

Hit ESCAPE key if you run the code

I suppose whoever coded the original FOR NEXT loop noticed that wrap around, so had to add extra code to prevent the endless loop.

However, the following code has only one IF condition and after exit the B counter has a value that matches A

Nothing is going wrong, except the programmer’s basic knowledge is flawed and they need to go back to school.

DIM b AS _UNSIGNED _BYTE
IF b > 255 THEN …..

Now tell me, what value you can assign to b to EVER make that IF statement a true condition so that it triggers??

b is an unsigned byte, as defined.  It’s value can ONLY be 0 to 255, and defined by the programmer.  Ergo, it’ll NEVER be greater than 255 and trigger that IF condition which exits the DO… LOOP…


So, with that part of the issue settled, let’s talk about limits of variables.

DIM b AS _UNSIGNED _BYTE
b = 255 + 1

Now, with the above, our variable b is defined as an unsigned byte and has to be in a range from 0 to 255…. Yet, we’re forcibly trying to make it hold a 2-byte value inside a 1-byte block of memory…

How does the language handle that???

You can shove a fully grown man into a child’s pair of pants, and you can’t shove a value of 256 into a single byte.  It’s just not possible.

So either you:

1) Cuss loudly, toss the pants on the floor in frustration and stop trying completely — the programming equivalent of tossing a terminating error saying “Variable Out of Bounds”, or some such, which completely halts execution…

OR:

2) You pull the pants up over as much of the ankles and toes as they can fit, and then say, “I did it!  Here’s the solution!  They fit (this much)…”

In programming, this is a simple case of OVERFLOW math.  Your return variable is 1-byte in size, so you return 1 byte.  The value 256 is stored in memory as 2 bytes (1 byte representing 1 * 256, and 1 byte representing 0).  The return value is the single byte that fits the size of your return variable type — in this case, that’s the byte representing zero, which gives a result of:

b = 255 + 1
PRINT b

b prints out “0”.

You overflowed the maximum value b could hold, so it took the bytes you designated for it and tossed out the rest.

For our pants analogy, we shaved someone’s feet and ankles into the child’s pants, and then cut the leg off above it and said, “See, it works!”


It’s not an error — it’s how the language is designed.  If you need b to become a value greater than 255, define it as an INTEGER and not an _UNSIGNED _BYTE.

Or else learn to do this:

b = 0
DO
   ….stuff
   IF b = 255 THEN
      EXIT DO
    ELSE
      b = b + 1
    END IF
LOOP

Now you exit before you overflow, and there’s no problem.

[SMcNeill]

I’ve never had a plate of spaghetti laid out before me, with every noodle lined up in a straight row.  If someone did, would it still be called “spaghetti”, or would it be “linear noodle art”?

Spaghetti is the jumbling up and interweaving of many strands of noodles, to the point where it’s impossible to find the start of one and the end of the other…

Spaghetti code, to me, follows this same basic concept.  As long as the code reads linearly from top to bottom, it’s not “spaghetti code”.  Now, when it suddenly starts executing where you read it from top to bottom to middle to bottom to top to middle to top….   Then THAT’s spaghetti code.

DO
   EXIT DO

The above reads top to bottom, so no spaghetti code there, in my opinion.

DO
    GOTO Do_Exit
LOOP
Do_Exit:

Same…. A simple goto to move program flow down the screen.  No spaghetti twisting there.


Foo:
DO
   IF Invalid_Input GOTO Foo


Now here we have spaghetti code!  (In my opinion.). We read top, down, as  usual, and then are suddenly instructed to scroll back up and read what’s above us.  We just “twisted” the reading logic of our program.

For me, at least, as long as the code continues to be readable in a linear fashion, it’s not “spaghetti code” — even if it contains EXITs, GOTOs, or other such flow controls.  It’s when the code requires us to skip up and down in it, to read and understand it, that I’d consider it “spaghettified”.

[Cobalt]

Here follows what would be considered a trivial example of spaghetti code in BASIC. The program prints each of the numbers 1 to 100 to the screen along with its square. Indentation is not used to differentiate the various actions performed by the code, and the program's GOTO statements create a reliance on line numbers. The flow of execution from one area to another is harder to predict. Real-world occurrences of spaghetti code are more complex and can add greatly to a program's maintenance costs.

Code: QB64: [Select]

1. 1 i=0
2. 2 i=i+1
3. 3 PRINT i; "squared=";i*i
4. 4 IF i>=100 THEN GOTO 6
5. 5 GOTO 2
6. 6 PRINT "Program Completed."
7. 7 END

Here is the same code written in a structured programming style:

Code: QB64: [Select]

1. 1 FOR i=1 TO 100
2. 2     PRINT i;"squared=";i*i
3. 3 NEXT i
4. 4 PRINT "Program Completed."
5. 5 END

The program jumps from one area to another, but this jumping is formal and more easily predictable, because for loops and functions provide flow control whereas the goto statement encourages arbitrary flow control. Though this example is small, real world programs are composed of many lines of code and are difficult to maintain when written in a spaghetti code fashion.

[George McGinn]

This program from the 1970's is TRUE spaghetti code:

Code: QB64: [Select]

1. _TITLE "BASEBALL (TEXT VERSION)"
2.  
3. REM "BASEBALL SIMULATION PROGRAM (TEXT MODE)
4. REM "A VERSION OF THIS PROGRAM RAN ON THE ALTAIR 8800 8K BASIC (1977)
5. REM "WRITTEN BY JOEL LIND & KEN BIRKMAN - NYU - JULY 1973
6. REM "STOLEN AND ENHANCED DECEMBER 1973 BY R. D. KURLAND - NYU
7. REM "RESTOLEN AND CONVERTED TO RUN IN TECHBASIC (JULY 7, 2020) BY GEORGE MCGINN
8. REM "CONVERTED FROM TECHBASIC TO QB64 (JULY 7, 2020) BY GEORGE MCGINN
9.  
10. '***************************************************
11. ' SETUP SCREEN FORMAT & SIZE, FONT TYPE & SIZE
12. '***************************************************
13.  
14. '*** Setup Screen Format and Size
15. SCREEN 0
16. SCREEN _NEWIMAGE(800, 700, 32)
17.  
18. '*** Setup and load Font Type, Format and Size
19. fontpath$ = "Veranda.tff"
20. font& = _LOADFONT(fontpath$, 16, "")
21.  
22.  
23. 130 DIM B(7), P$(9), W$(7), J$(8), K$(4)
24. 140 FOR I = 1 TO 7: B(I) = 0: NEXT
25. 150 BA = 0: T9 = 0: R9 = 0: S = 0: O = 0: B1 = 0: B2 = 0: T = 0
26. 160 Z1 = 1: Z2 = 1
27. 170 PRINT "WELCOME TO EBBETT'S FIELD"
28. 180 PRINT "WHAT DO YOU WANT TO CALL YOUR TEAM ";
29. 190 INPUT A$
30. 200 FOR I = 1 TO 7: READ W$(I): NEXT
31. 210 FOR I = 1 TO 9: READ P$(I): NEXT
32. 220 FOR I = 1 TO 4: READ K$(I): NEXT
33. 230 FOR I = 1 TO 8: READ J$(I): NEXT
34. 240 PRINT "FINE. THE "; A$; " NEED A MANAGER. WHAT'S YOUR NAME ";
35. 250 INPUT B$
36. 260 PRINT "WHAT DO YOU WANT TO CALL MY TEAM, "; B$;
37. 270 INPUT C$
38. 280 PRINT
39. 290 PRINT "OPENING DAY, THE "; A$; " VERSUS THE "; C$
40. 300 PRINT
41. 310 PRINT "LET'S FLIP A COIN. THE WINNER IS THE HOME TEAM."
42. 320 PRINT "HEADS OR TAILS ";
43. 330 INPUT D$: D$ = UCASE$(D$)
44. 340 IF D$ <> "HEADS" AND D$ <> "TAILS" THEN GOTO 320
45. 350 FOR I = 1 TO TYM
46.    360 Y = RND(1)
47. 370 NEXT I
48. 380 H = 1
49. 390 Y = RND(1)
50. 400 Y$ = "HEADS"
51. 410 IF Y > .5 THEN Y$ = "TAILS"
52. 420 IF D$ = Y$ THEN 490
53. 430 H = 0
54. 440 PRINT "YOU LOST THE TOSS. THE "; A$; " ARE UP FIRST."
55. 450 PRINT
56. 460 PRINT
57. 470 A = 0
58. 480 GOTO 610
59. 490 PRINT "YOU WIN THE TOSS. "; A$; " TAKE THE FIELD, AND ";
60. 500 PRINT C$; " ARE AT BAT."
61. 510 A = 1
62. 520 R9 = 0
63. 530 T = T + 1
64. 540 IF T < 18 THEN GOSUB 5140
65. 550 IF T < 18 THEN 710
66. 560 IF T > 18 THEN 590
67. 570 GOSUB 3500
68. 580 GOTO 710
69. 590 GOSUB 3290
70. 600 GOTO 710
71. 610 REM START AN INNING - WE ARE OUT ON THE FIELD
72. 620 T = T + 1
73. 630 R9 = 0
74. 640 IF T < 18 THEN 690
75. 650 IF T > 18 THEN 680
76. 660 GOSUB 3500
77. 670 GOTO 690
78. 680 GOSUB 3290
79. 690 REM IF T>2 THEN 710
80. 700 GOSUB 5070
81. 710 S = 0: BA = 0
82. 720 PRINT
83. 730 IF O = 0 THEN PRINT "NO OUTS"
84. 740 IF O = 1 THEN PRINT "THERE IS 1 OUT"
85. 750 IF O > 1 THEN PRINT "THERE ARE "; O; " OUTS"
86. 760 P = B(1) + B(2) + B(3)
87. 770 IF P <> 3 THEN 800
88. 780 PRINT "BASES LOADED"
89. 790 GOTO 900
90. 800 IF P = 0 THEN 900
91. 810 Y$ = "RUNNER ON "
92. 820 IF P > 1 THEN Y$ = "RUNNERS ON "
93. 830 PRINT Y$;
94. 840 IF B(1) = 0 THEN 870
95. 850 PRINT "FIRST";
96. 860 IF P > 1 THEN PRINT " AND ";
97. 870 IF B(2) = 1 THEN PRINT "SECOND";
98. 880 IF P > 1 AND B(1) = 0 THEN PRINT " AND ";
99. 890 IF B(3) = 1 THEN
100.     PRINT "THIRD"
101. ELSE
102.     PRINT " "
103. END IF
104. 900 IF A = 0 THEN 920
105. 910 GOTO 3030
106. 920 PRINT "BATTER UP"
107. 930 IF BA <> 3 OR S <> 2 THEN 960
108. 940 PRINT "FULL COUNT"
109. 950 GOTO 970
110. 960 IF BA > 0 OR S > 0 THEN PRINT "THE COUNT IS "; BA; " AND "; S
111. 970 PRINT
112. 980 IF A = 1 THEN 3030
113. 990 PRINT "WHAT WILL YOUR BATTER DO, "; B$;
114. 1000 INPUT C
115. 1010 IF C > 0 AND C < 5 THEN GOTO 1050
116. 1020 PRINT "HUH?  ";
117. 1030 GOSUB 5070
118. 1040 GOTO 990
119. 1050 Y2 = RND(1)
120. 1060 IF Y2 < .56 OR Y2 > .5625 THEN GOTO 1120
121. 1070 PRINT "WILD PITCH!"
122. 1080 N = 1
123. 1090 GOSUB 3540
124. 1100 B(1) = 0
125. 1110 GOTO 1210
126. 1120 IF Y2 > .772 AND Y2 < .775 THEN 4880
127. 1130 ON C GOTO 1140, 1450, 2600, 4450, 5500
128. 1140 C = 1
129. 1150 GOSUB 5240
130. 1160 IF A = 0 THEN Z1 = Z1 + 1
131. 1170 Y = RND(1)
132. 1180 IF BA <> 3 OR S <> 0 THEN 1200
133. 1190 IF Y < .7 THEN GOTO 1310 ELSE GOTO 1210
134. 1200 IF Y < .5 THEN 1310
135. 1210 BA = BA + 1
136. 1220 Y = INT(RND(1) * 8 + 1)
137. 1230 IF Y = 9 THEN 1220
138. 1240 PRINT J$(Y); " - BALL "; BA
139. 1250 IF BA <> 4 THEN 930
140. 1260 PRINT "WALK"
141. 1270 GOSUB 4950
142. 1280 Y = RND(1)
143. 1290 GOTO 710
144. 1300 PRINT "HIGH POP - FOUL DOWN THE "; Y$; " FIELD LINE"
145. 1310 S = S + 1
146. 1320 IF C = 2 OR C = 5 THEN GOTO 1370
147. 1330 Y = INT(RND(1) * 4 + 1)
148. 1340 IF Y = 5 THEN 1330
149. 1350 PRINT K$(Y); ", CALLED STRIKE "; S
150. 1360 GOTO 1380
151. 1370 PRINT "SWINGING STRIKE "; S
152. 1380 IF C = 5 AND S <> 3 THEN 4450
153. 1390 IF S <> 3 THEN 930
154. 1400 PRINT "STRUCK OUT"
155. 1410 O = O + 1
156. 1420 IF O = 3 THEN 2850
157. 1430 IF C = 5 THEN 4450
158. 1440 GOTO 710
159. 1450 C = 2
160. 1460 Y = INT(RND(1) * 10 + 1)
161. 1470 IF Y = 10 THEN 1450
162. 1480 IF A = 0 THEN Z2 = Z2 + 1
163. 1490 IF C <> 5 THEN GOSUB 5240
164. 1500 IF S <> 2 AND Z2 / Z1 > 7 AND A = 0 THEN 1520
165. 1510 IF S <> 2 OR Z2 / Z1 < 25 THEN 1590
166. 1520 Y = INT(RND(1) * 20 + 1)
167. 1530 IF Y > 7 THEN 1550
168. 1540 ON Y GOTO 1610, 1310, 1310, 1310, 1310, 1680, 1610
169. 1550 IF Y > 13 THEN 1570
170. 1560 ON Y - 7 GOTO 1680, 1310, 1740, 1850, 1740, 1850
171. 1570 IF Y > 18 THEN 1600
172. 1580 ON Y - 13 GOTO 1980, 1980, 2040, 2570, 1640, 2570
173. 1590 IF Y < 3 THEN 1310
174. 1600 ON Y - 2 GOTO 1610, 1680, 1740, 1850, 1980, 2040, 2570
175. 1610 PRINT "FOULED INTO THE STANDS-OUT OF PLAY"
176. 1620 IF S <> 2 THEN S = S + 1
177. 1630 GOTO 930
178. 1640 Y = RND(1)
179. 1650 Y$ = "RIGHT"
180. 1660 IF Y < .5 THEN Y$ = "LEFT"
181. 1670 GOTO 1620
182. 1680 Y = INT(RND(1) * 20 + 1)
183. 1690 IF Y > 18 THEN 1720
184. 1700 PRINT "FOULED BACK INTO THE STANDS"
185. 1710 GOTO 1620
186. 1720 PRINT "POPPED IT UP - CAUGHT BY CATCHER"
187. 1730 GOTO 1410
188. 1740 PRINT "INFIELD GROUNDER"
189. 1750 E2 = RND(1)
190. 1760 IF E2 < .37 OR E2 > .41 THEN 1820
191. 1770 PRINT "1 BASE ERROR!!"
192. 1780 N = 1
193. 1790 C = 4
194. 1800 GOSUB 3540
195. 1810 GOTO 710
196. 1820 GOSUB 4100
197. 1830 IF O = 3 THEN 2850
198. 1840 GOTO 710
199. 1850 PRINT "GROUNDER - COULD BE TROUBLE - "
200. 1860 Y = RND(1)
201. 1870 IF Y > .75 THEN 1950
202. 1880 Y$ = "UP THE MIDDLE"
203. 1890 IF Y < .5 THEN Y$ = "THROUGH THE HOLE INTO RIGHT FIELD"
204. 1900 IF Y < .25 THEN Y$ = "THROUGH THE HOLE INTO LEFT FIELD"
205. 1910 PRINT "A SINGLE "; Y$; "!"
206. 1920 N = 1
207. 1930 GOSUB 3540
208. 1940 GOTO 710
209. 1950 PRINT "INFIELDER UP WITH IT!"
210. 1960 GOSUB 4800
211. 1970 IF O = 3 THEN GOTO 2850 ELSE GOTO 710
212. 1980 Y = RND(1)
213. 1990 Y$ = "LEFT"
214. 2000 IF Y < .6 THEN Y$ = "CENTER"
215. 2010 IF Y < .3 THEN Y$ = "RIGHT"
216. 2020 PRINT "FLY-OUT TO "; Y$; " FIELD"
217. 2030 GOTO 1410
218. 2040 Z = RND(1)
219. 2050 Y$ = "CENTER"
220. 2060 IF Z < .6 THEN Y$ = "RIGHT"
221. 2070 IF Z < .3 THEN Y$ = "LEFT"
222. 2080 PRINT "LONG FLY TO DEEP "; Y$; " FIELD - LOOKS GOOD! "
223. 2090 Z = RND(1)
224. 2100 IF Z < .9 THEN 2130
225. 2110 PRINT Y$; "FIELDER CAUGHT IT AT THE WALL!"
226. 2120 GOTO 2180
227. 2130 IF Z < .8 THEN 2160
228. 2140 PRINT "A DIVING CATCH!"
229. 2150 GOTO 2180
230. 2160 IF Z < .7 THEN 2290
231. 2170 PRINT Y$; "FIELDER CAUGHT IT ON THE WARNING TRACK!"
232. 2180 O = O + 1
233. 2190 IF O = 3 THEN 2850
234. 2200 FOR I = 3 TO 1 STEP -1
235.    2210 IF B(I) = 1 THEN 2240
236. 2220 NEXT I
237. 2230 GOTO 710
238. 2240 B(I + 1) = B(I)
239. 2250 B(I) = 0
240. 2260 PRINT "LEAD RUNNER TAGS UP - AND ADVANCES 1 BASE!"
241. 2270 GOSUB 3830
242. 2280 GOTO 710
243. 2290 IF Z < .5 THEN 2360
244. 2300 PRINT "BATTER HOLDS WITH A SINGLE."
245. 2310 N = 2
246. 2320 GOSUB 3540
247. 2330 B(2) = 0
248. 2340 B(1) = 1
249. 2350 GOTO 710
250. 2360 IF Z < .15 THEN 2480
251. 2370 PRINT "DOUBLE!"
252. 2380 Y = RND(1)
253. 2390 IF Y > .5 THEN 2430
254. 2400 N = 2
255. 2410 GOSUB 3540
256. 2420 GOTO 710
257. 2430 N = 3
258. 2440 GOSUB 3540
259. 2450 B(3) = 0
260. 2460 B(2) = 1
261. 2470 GOTO 710
262. 2480 IF Z < .1 THEN 2530
263. 2490 PRINT "TRIPLE!"
264. 2500 N = 3
265. 2510 GOSUB 3540
266. 2520 GOTO 710
267. 2530 PRINT "IT'S OVER THE WALL -- A H*O*M*E R*U*N!!!"
268. 2540 N = 4
269. 2550 GOSUB 3540
270. 2560 GOTO 710
271. 2570 Y = INT(RND(1) * 7 + 1)
272. 2580 PRINT "LINED OUT TO "; P$(Y)
273. 2590 GOTO 1410
274. 2600 GOSUB 5240
275. 2610 PRINT "BATTER BUNTS... "
276. 2620 Y = RND(1)
277. 2630 IF Y < .6 THEN 2750
278. 2640 IF B(3) = 0 THEN 2660
279. 2650 IF Y < .8 THEN 2830
280. 2660 PRINT "THROWN OUT AT FIRST."
281. 2670 O = O + 1
282. 2680 IF O = 3 THEN 2850
283. 2690 IF B(1) + B(2) + B(3) = 0 THEN 710
284. 2700 PRINT "SACRIFICE - ";
285. 2710 N = 1
286. 2720 GOSUB 3540
287. 2730 B(1) = 0
288. 2740 GOTO 710
289. 2750 IF Y < .2 THEN 2830
290. 2760 IF Y < .4 THEN 2790
291. 2770 PRINT "BATTER MISSES PITCH"
292. 2780 GOTO 1310
293. 2790 PRINT "BEATS IT OUT! SINGLE!"
294. 2800 N = 1
295. 2810 GOSUB 3540
296. 2820 GOTO 710
297. 2830 GOSUB 4100
298. 2840 IF O <> 3 THEN 710
299. 2850 PRINT "3 OUTS. THE SIDE IS RETIRED";
300. 2860 I = B(1) + B(2) + B(3)
301. 2870 IF I = 0 THEN PRINT "."
302. 2880 IF I = 1 THEN PRINT ", LEAVING 1 MAN ON BASE"
303. 2890 IF I > 1 THEN PRINT ", LEAVING "; I; " MEN ON BASE"
304. 2900 PRINT
305. 2910 PRINT
306. 2920 PRINT "*************"
307. 2930 D = T / 2 - INT(T / 2)
308. 2940 PRINT "AFTER ";
309. 2950 IF T > 1 THEN PRINT INT(T / 2); " ";
310. 2960 IF D > .3 THEN PRINT "1/2 ";
311. 2970 Y$ = "INNINGS"
312. 2980 IF T < 3 THEN Y$ = "INNING"
313. 2990 PRINT Y$; " OF PLAY, THE SCORE IS"
314. 3000 GOSUB 3960
315. 3010 O = 0: B(1) = 0: B(2) = 0: B(3) = 0
316. 3020 IF A = 0 THEN GOTO 510 ELSE GOTO 470
317. 3030 REM MY TEAM IS AT BAT
318. 3040 Y = RND(1)
319. 3050 IF B(1) + B(2) + B(3) = 0 THEN 3140
320. 3060 REM IF O=2 AND S=2 AND B=3 THEN 4850
321. 3070 IF B(3) = 1 THEN 3110
322. 3080 IF B(2) = 0 THEN 3100
323. 3090 IF .45 < Y AND .46 > Y THEN 4450
324. 3100 IF .45 < Y AND .47 > Y THEN 4450
325. 3110 IF O = 2 THEN 3140
326. 3120 IF O < 2 AND Y < .333 AND B(3) = 1 THEN 2600
327. 3130 IF .45 < Y AND .55 > Y THEN 2600
328. 3140 IF S = 0 THEN 3240
329. 3150 IF BA <> 3 THEN GOTO 3180
330. 3160 IF Y < .6 THEN GOTO 1450
331. 3170 GOTO 1140
332. 3180 IF Y > .3 THEN GOTO 1450
333. 3190 IF S <> 2 THEN GOTO 1140
334. 3200 IF BA = 0 AND Y < .1 THEN GOTO 1140
335. 3210 IF BA = 0 THEN GOTO 1450
336. 3220 IF Y < .2 THEN GOTO 1140
337. 3230 GOTO 1450
338. 3240 IF BA = 3 THEN GOTO 3270
339. 3250 IF Y < .6 THEN GOTO 1140
340. 3260 GOTO 1450
341. 3270 IF Y < .9 THEN GOTO 1140
342. 3280 GOTO 1450
343. 3290 IF T <> 19 THEN GOTO 3330
344. 3300 IF R1 <> R2 THEN GOTO 3340
345. 3310 PRINT
346. 3320 PRINT "*** GOING INTO EXTRA INNINGS ***"
347. 3330 IF R1 = R2 THEN RETURN
348. 3340 IF (T - 1) / 2 <> INT(T - 1) / 2 THEN RETURN
349. 3350 PRINT "THE BALLGAME IS OVER."
350. 3360 PRINT "*************"
351. 3370 PRINT "FINAL SCORE:"
352. 3380 T9 = 1
353. 3390 GOSUB 3960
354. 3400 IF R1 > R2 THEN 3470
355. 3410 PRINT "NICE TRY, "; B$
356. 3420 PRINT "YOU SHOULD KNOW BETTER THAN TO TRY TO"
357. 3430 PRINT "OUT-MANAGE A COMPUTER.  MAYBE BASEBALL"
358. 3440 PRINT "JUST ISN'T YOUR SPORT...WHY DON'T YOU TRY GOLF?"
359. 3450 REM CHAIN GOLF
360. 3460 STOP
361. 3470 PRINT "CONGRATULATIONS, "; B$
362. 3480 PRINT "YOU'VE BEATEN ME, BUT I WILL HAVE MY REVENGE."
363. 3490 STOP
364. 3500 REM 9TH INNING
365. 3510 IF A = 0 THEN 3530
366. 3520 IF R2 > R1 THEN GOTO 3350 ELSE RETURN
367. 3530 IF R1 > R2 THEN GOTO 3350 ELSE RETURN
368. 3540 REM ADVANCE N BASES (SET N BEFORE GOSUB)
369. 3550 N2 = B(1) + B(2) + B(3)
370. 3560 IF C = 5 THEN N = N + 1
371. 3570 N3 = N
372. 3580 IF N2 = 0 THEN 3650
373. 3590 REM FIND LAST RUNNER: MAKE SURE HE ISN‘T TRYING TO ADVANCE
374. 3600 REM PAST HOME PLATE.
375. 3610 FOR I = 1 TO 3
376.    3620 IF B(I) = 1 THEN 3640
377. 3630 NEXT I
378. 3640 IF 4 - I < N THEN N3 = 4 - I
379. 3650 FOR I = 3 + N TO N + 1 STEP -1
380.    3660 B(I) = B(I - N)
381. 3670 NEXT I
382. 3680 B(N) = 1
383. 3690 IF N = 1 THEN 3740
384. 3700 FOR P = 1 TO 3
385.    3710 IF (N - P) > 1 THEN B(N - P) = 0
386.    3720 IF (N - P) <= 1 THEN B(1) = 0
387. 3730 NEXT P
388. 3740 FOR P = 1 TO 7
389.    3750 IF P = N THEN 3780
390. 3760 NEXT P
391. 3770 GOTO 3830
392. 3780 IF C = 4 OR N2 = 0 THEN 3830
393. 3790 Y$ = "RUNNERS ADVANCE "
394. 3800 IF N2 = 1 THEN Y$ = "RUNNER ADVANCES "
395. 3810 PRINT Y$; N3;
396. 3820 IF N3 = 1 THEN
397.     PRINT " BASE"
398. ELSE
399.     PRINT " BASES"
400. END IF
401. 3830 IF B(4) + B(5) + B(6) + B(7) = 0 THEN RETURN
402. 3840 REM AT LEAST 1 RUN HAS SCORED.
403. 3850 N2 = B(4) + B(5) + B(6) + B(7)
404. 3860 IF A = 0 THEN 3890
405. 3870 R2 = R2 + N2
406. 3880 GOTO 3900
407. 3890 R1 = R1 + N2
408. 3900 B(4) = 0: B(5) = 0: B(6) = 0: B(7) = 0
409. 3910 IF N2 = 1 THEN PRINT "** 1 RUN SCORED"
410. 3920 IF N2 > 1 THEN PRINT "** "; N2; " RUNS SCORED"
411. 3930 PRINT
412. 3940 PRINT
413. 3950 PRINT "******** NEW SCORE:"
414. 3960 IF H = 1 THEN 4000
415. 3970 IF LEN(A$) > LEN(C$) THEN PRINT A$; TAB(LEN(A$) + 3); R1
416. 3980 IF LEN(A$) <= LEN(C$) THEN PRINT A$; TAB(LEN(C$) + 3); R1
417. 3990 IF H = 1 THEN 4030
418. 4000 IF LEN(A$) > LEN(C$) THEN PRINT C$; TAB(LEN(A$) + 3); R2
419. 4010 IF LEN(A$) <= LEN(C$) THEN PRINT C$; TAB(LEN(C$) + 3); R2
420. 4020 IF H = 1 THEN 3970
421. 4030 PRINT "*************"
422. 4040 PRINT
423. 4050 PRINT
424. 4060 IF T9 = 1 THEN 4090
425. 4070 IF A = 1 AND T > 17 AND INT(T / 2) = T / 2 AND R2 > R1 THEN 3350
426. 4080 IF A = 0 AND T > 17 AND INT(T / 2) = T / 2 AND R1 > R2 THEN 3350
427. 4090 RETURN
428. 4100 REM LEAD RUNNER OUT (FIELDER‘S CHOICE THEN ONE BASE ADVANCE)
429. 4110 N = 1
430. 4120 I = 4
431. 4130 IF B(4) = 0 AND B(3) = 1 AND B(2) = 1 AND B(1) = 1 THEN 4220
432. 4140 I = 3
433. 4150 IF B(3) = 0 AND B(2) = 1 AND B(1) = 1 THEN 4220
434. 4160 I = 2
435. 4170 IF B(2) = 0 AND B(1) = 1 THEN 4220
436. 4180 REM NO ONE FORCED
437. 4190 O = O + 1
438. 4200 PRINT "BATTER THROWN OUT"
439. 4210 RETURN
440. 4220 B(I - 1) = 0
441. 4230 F = RND(1)
442. 4240 IF O = 2 OR F > .3 THEN 4290
443. 4250 O = O + 2
444. 4260 PRINT "DOUBLE PLAY!"
445. 4270 IF O = 3 THEN RETURN
446. 4280 GOTO 4910
447. 4290 O = O + 1
448. 4300 PRINT "RUNNER ON BASE "; I - 1; " IS OUT ON FIELDER'S CHOICE"
449. 4310 IF O = 3 THEN RETURN
450. 4320 GOSUB 3540
451. 4330 RETURN
452. 4340 REM FORCED RUNNERS ADVANCE 1 BASE, OTHERS HOLD
453. 4350 FOR I = 1 TO 3
454.    4360 IF B(I) = 0 THEN 4400
455. 4370 NEXT I
456. 4380 N = 1
457. 4390 GOTO 3540
458. 4400 REM NO ONE ON BASE I
459. 4410 FOR I2 = I TO 1 STEP -1
460.    4420 B(I2) = 1
461. 4430 NEXT I2
462. 4440 RETURN
463. 4450 REM LEAD RUNNER STEALS
464. 4460 FOR I = 3 TO 1 STEP -1
465.    4470 IF B(I) = 1 THEN 4510
466. 4480 NEXT I
467. 4490 PRINT "NO ONE ON BASE, DUMMY!"
468. 4500 GOTO 990
469. 4510 REM I IS LEAD RUNNER‘S BASE
470. 4520 IF C <> 5 THEN GOSUB 5240
471. 4530 IF RND(1) / I < .3 THEN 4680
472. 4540 IF B(1) + B(2) + B(3) > 1 THEN 4570
473. 4550 PRINT "RUNNER STEALS A BASE"
474. 4560 GOTO 4580
475. 4570 PRINT "RUNNERS STEAL A BASE"
476. 4580 N = 1
477. 4590 C2 = C
478. 4600 C = 4
479. 4610 GOSUB 3540
480. 4620 C = C2
481. 4630 B(1) = 0
482. 4640 IF C = 5 AND S <> 3 THEN 930
483. 4650 IF C = 5 THEN 710
484. 4660 Y = RND(1)
485. 4670 IF Y > .5 THEN GOTO 1210 ELSE GOTO 1310
486. 4680 PRINT "RUNNER THROWN OUT STEALING"
487. 4690 O = O + 1
488. 4700 B(I) = 0
489. 4710 IF O = 3 THEN GOTO 2850
490. 4720 N = 1
491. 4730 GOSUB 3540
492. 4740 B(1) = 0
493. 4750 IF C = 5 AND S <> 3 THEN GOTO 930
494. 4760 IF C = 5 THEN GOTO 710
495. 4770 Y = RND(1)
496. 4780 IF BA = 3 THEN GOTO 1310
497. 4790 IF Y > .5 THEN GOTO 1210 ELSE GOTO 1310
498. 4800 REM RUNNERS ADVANCE ONE BASE, BATTER THROWN OUT
499. 4810 N = 1
500. 4820 IF O = 2 THEN 4850
501. 4830 GOSUB 3540
502. 4840 B(1) = 0
503. 4850 O = O + 1
504. 4860 PRINT "BATTER THROWN OUT"
505. 4870 RETURN
506. 4880 PRINT "HIT BATSMAN (OUCH!)"
507. 4890 GOSUB 4950
508. 4900 GOTO 710
509. 4910 N = 1
510. 4920 GOSUB 3540
511. 4930 B(1) = 0
512. 4940 RETURN
513. 4950 REM BATTER WALKED
514. 4960 FOR I = 1 TO 3
515.    4970 IF B(I) = 0 THEN 5010
516. 4980 NEXT I
517. 4990 N = 1
518. 5000 GOTO 3540
519. 5010 IF I = 1 THEN 5050
520. 5020 FOR I0 = I TO 2 STEP -1
521.    5030 B(I0) = B(I0 - 1)
522. 5040 NEXT I0
523. 5050 B(1) = 1
524. 5060 RETURN
525. 5070 PRINT "WHEN YOUR'RE UP:"
526. 5080 PRINT "1-BATTER TAKES PITCH"
527. 5090 PRINT "2-BATTER SWINGS AWAY"
528. 5100 PRINT "3-BATTER BUNTS"
529. 5110 PRINT "4-LEAD RUNNER STEALS"
530. 5120 REM PRINT "5-HIT AND RUN"
531. 5130 RETURN
532. 5140 REM PITCHING ROUTINE
533. 5150 PRINT "YOUR PITCHER MAY THROW:"
534. 5160 PRINT "1-FAST BALL"
535. 5170 PRINT "2-CURVE"
536. 5180 PRINT "3-SLIDER"
537. 5190 PRINT "4-SINKER"
538. 5200 PRINT "5-CHANGE-UP"
539. 5210 PRINT "6-KNUCKLEBALL"
540. 5220 PRINT "7-SCREWBALL"
541. 5230 RETURN
542. 5240 IF A = 0 THEN 5370
543. 5250 IF R9 = 1 THEN 5300
544. 5260 PRINT "WHAT WILL YOUR PITCHER THROW? ";
545. 5270 INPUT W
546. 5280 IF W < 0 THEN R9 = 1
547. 5290 IF R9 = 0 THEN GOTO 5320 ELSE PRINT "RANDOM PITCHES FOR REST OF INNING"
548. 5300 W = INT(RND(1) * 8 + 1)
549. 5310 IF W = 8 THEN 5300
550. 5320 IF W > 0 AND W < 8 THEN 5470
551. 5330 PRINT "UH-UH, "; B$; ".  ";
552. 5340 GOSUB 5150
553. 5350 PRINT
554. 5360 GOTO 5260
555. 5370 REM I MUST SELECT A PITCH
556. 5380 W1 = RND(1)
557. 5390 W = 1
558. 5400 IF W1 < .75 THEN W = 2
559. 5410 IF W1 < .55 THEN W = 3
560. 5420 IF W1 < .45 THEN W = 4
561. 5430 IF W1 < .35 THEN W = 5
562. 5440 IF W1 < .15 THEN W = 6
563. 5450 IF W1 < .08 THEN W = 7
564. 5460 GOTO 5470
565. 5470 PRINT W$(W);
566. 5480 PRINT "...";
567. 5490 RETURN
568. 5500 REM HIT-AND-RUN
569. 5510 IF B(1) + B(2) + B(3) = 0 THEN 4490
570. 5520 GOSUB 5240
571. 5530 PRINT "HIT AND RUN!"
572. 5540 C = 5
573. 5550 GOTO 1460
574. 5560 DATA FAST BALL,CURVE BALL,SLIDER,SINKER,CHANGE-UP,KNUCKLEBALL
575. 5570 DATA SCREWBALL
576. 5580 DATA RIGHT,LEFT,CENTER,FIRST,SECOND,THIRD,SHORTSTOP,PITCHER,CATCHER
577. 5590 DATA RIGHT OVER THE PLATE,CAUGHT THE OUTSIDE CORNER
578. 5600 DATA OVER THE INSIDE CORNER,OVER AT THE KNEES
579. 5610 DATA HIGH,LOW,INSIDE,OUTSIDE,HIGH AND TIGHT,LOW AND OUTSIDE
580. 5620 DATA LOW AND INSIDE,HIGH AND OUTSIDE
581. 5630 END
582.  

[Cobalt]

This program from the 1970's is TRUE spaghetti code:

Agreed.

[Pete]

All three of these will equal 10 after the loop is completed.

Code: QB64: [Select]

1. max = 10
2. DO
3.     i = i + 1
4. LOOP UNTIL i = max
5. PRINT i
6.  
7. ' Or...
8.  
9. max = 10
10. FOR i = 1 TO max
11. NEXT
12. i = i - 1 ' Sets value of i to max.
13. PRINT i
14.  
15. ' Or...
16.  
17. max = 10
18. FOR i = 1 TO max
19.     IF i = max THEN EXIT FOR
20. NEXT
21. PRINT i
22.  

I've used all 3 if I'm concerned about the value of the i variable becoming one-extra in a FOR/NEXT loop. Really, as has been stated, it's just understanding the nature of the code.

So are the any reasonable reasons FOR NEXT increases the value of the loop variable by one upon completion? I can give one...

Code: QB64: [Select]

1. FOR i = 1 TO 10
2.     PRINT i
3. NEXT
4.  
5. FOR j = i TO i - 1 + 10
6.     PRINT j
7. NEXT
8.  
9. PRINT: PRINT "i and j ="; i; j

So the variable FOR/NEXT increase on completion is required for progressive output, otherwise the 10th output would be repeated.

Pete

If this is food for thought, where the hell is the mustard?

[bplus]

@Cobalt  show me your flag trick for this:

Code: QB64: [Select]

1. Input "enter x"; x
2. i = 1
3. Do
4.     Print "i ="; i
5.     If x - i < 0 Then Exit Do ' avoid  print neg sqr  error
6.     Print "SQR(input - i) ="; Sqr(x - i)
7.     i = i + 1
8. Loop Until i = 10
9.  

[Cobalt]

@bplus

you could simply:

Code: QB64: [Select]

1. INPUT "enter x"; x
2. i = 1
3. DO
4.  PRINT "i ="; i
5.  IF x - i >= 0 THEN  PRINT "SQR(input - i) ="; SQR(x - i) else i = 9
6.  i = i + 1
7. LOOP UNTIL i = 10

Or even:

Code: QB64: [Select]

1. INPUT "enter x"; x
2. i = 1
3. DO
4.  PRINT "i ="; i
5.  IF x - i < 0 THEN Flag%% = -1: i = 9
6.  IF NOT Flag%% THEN PRINT "SQR(input - i) ="; SQR(x - i)
7.  i = i + 1
8. LOOP UNTIL i = 10

 here as well:

Code: QB64: [Select]

1. INPUT "enter x"; x
2. i = 1
3. DO
4.  PRINT "i ="; i
5.  IF x - i < 0 THEN Flag%% = -1
6.  IF NOT Flag%% THEN PRINT "SQR(input - i) ="; SQR(x - i)
7.  i = i + 1
8. LOOP UNTIL i = 10 OR Flag%%

[bplus]

Thanks Cobalt, first looks really clean without flag :)

[bartok]

NOVARSEG,

Also the counter variable stays incremented after the FOR NEXT exits. So If A = 255,   B = 256 after the exit.  There are many times when this has caused hard to trace bugs.
 

i don't think so. It is perfectly logical that the variable, when the loops ends, is incremented: the last line is "NEXT". It will be strange if it doesn't. Furtheremore, it is a fact that it is no difficult at all to rembember, and it also possible that the variable has to be incremented when the loops end. If not, it is not a problem to add a line: x = x - 1.

OldMoses,

I generally find DO...LOOP and FOR...NEXT to be nearly interchangeable, and I tend to go for DOs more often, as I've heard it said that they are somewhat faster. I try to see what gets the job done in the least amount of code, using the philosophy that the best and most reliable part is no part.

I think they are very different instead. It is true that it is often possibile to use the one or the other in many issues, but the use is very diffent. The DO-LOOP cycle, not only allows to do loops of unknown steps, but, with DO-LOOP cycles nested in pairs, it is possibile to loop only a part of a specific DO-LOOP cycle, using EXIT DO, so that many times the DO-LOOP cycle, not only often exites with EXIT DO without reaching the condition of LOOP UNTIL, LOOP WHILE, DO UNTIL, DO WHILE, but it can also loops only a part of itself.
FOR-NEXT, it is very powerfull to make arrays for math purposes.