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Active Forums => Programs => Topic started by: Zeppelin on September 05, 2018, 04:40:08 am

Title: Help Saving and Loading Data
Post by: Zeppelin on September 05, 2018, 04:40:08 am

Hey,
I need some help loading data from a text file. For some reason when I call DO UNTIL EOF(1) there seems to be no data in the text file, even though there is.
The loaded data should be saved to an array.
The data is layed out in the format:
Name (str)
Health (int)
Atk (int)
Def (int)
Spd(int)

Any other performance tips or bugs found in the attached program, please let me know.

Thanks
Zeppelin

P.s What happened to the old forum? (I haven't been programming for a while and couldn't find it).

Title: Re: Help Saving and Loading Data
Post by: SMcNeill on September 05, 2018, 04:58:17 am

Change the DO WHILE EOF(1) to DO UNTIL EOF(1) and then try it.

Title: Re: Help Saving and Loading Data
Post by: Zeppelin on September 05, 2018, 05:05:26 am

Thanks SMcNeill,
Can't believe it was something so small and simple I was missing.

Title: Re: Help Saving and Loading Data
Post by: SMcNeill on September 05, 2018, 05:19:46 am

It's a subtle thing, but it completely reverses your loop conditions.  For example, compare the following 2 snippets:

DO WHILE hungry
    EatFood
LOOP


DO UNTIL hungry
     EatFood
LOOP

The first says you eat WHILE hungry; the second says to eat UNTIL you get hungry!  Basically with the second, if you're hungry, you refuse food until you die, or if you're full (not hungry), you just keep eatting until you die....

Title: Re: Help Saving and Loading Data
Post by: codeguy on September 05, 2018, 04:10:44 pm

do
'* some code in here
loop until not hungry

this executes code in the do/until loop at least once

Code: QB64: [Select]

1. x=1
2. do
3. x=x+1
4. loop until x>0
5.  

x will equal 2 because code in the do/until loop executes at least once.

Code: QB64: [Select]

1. x=1
2. do until x>0 * 'you can substitute while in place of until and the result will be the same for the prior and this example.
3. x=x+1
4. loop
5.  

x will equal 1 because the condition at the beginning of the do/loop has already been met.

Title: Re: Help Saving and Loading Data
Post by: codeguy on September 05, 2018, 04:27:56 pm

For larger programs, using FREEFILE to determine an available input or output channel may help.

Code: QB64: [Select]

1. 'SLAY V4 REMAKE
2. _TITLE "SLAY V4" 'SET TITLE
3. _FULLSCREEN 'SET FULLSCREEN
4. SCREEN 12
5.  
6. 'DECLARE VARIABLES
7. DIM saveData$(1000)
8.  
9. DIM SHARED player.name AS STRING
10. DIM SHARED player.health AS INTEGER
11. DIM SHARED player.atk AS INTEGER
12. DIM SHARED player.def AS INTEGER
13. DIM SHARED player.spd AS INTEGER
14.  
15. DIM SHARED w AS INTEGER
16. DIM SHARED h AS INTEGER
17.  
18. 'GET THE SCREEN DIMSENSIONS
19. w = _WIDTH
20. h = _HEIGHT
21.  
22. 'SET THE COLOR
23. col = _RGBA(255, 255, 255, 255)
24.  
25. 'LOAD SAVE DATA
26. SlayV4SaveDataChannel% = FREEFILE
27. IF SlayV4SaveDataChannel% > 0 THEN
28.     OPEN "SlayV4SaveData.txt" FOR INPUT AS #SlayV4SaveDataChannel%
29.     DO UNTIL EOF(SlayV4SaveDataChannel%) 'LOOP UNTIL END OF FILE
30.         filecount = filecount + 1 'COUNT AMOUNT OF LINES
31.         LINE INPUT #SlayV4SaveDataChannel%, file$
32.         saveData$(filecount) = file$
33.     LOOP
34.     CLOSE #SlayV4SaveDataChannel%
35. ELSE
36.     PRINT "Too many files open."
37.     _DELAY 3
38.     BEEP
39.     SYSTEM
40. END IF
41.  

Title: Re: Help Saving and Loading Data
Post by: Zeppelin on September 05, 2018, 06:53:34 pm

Thanks for the explications, quick reply and help, SMcNeill and CodeGuy.
I'll have a look into FREEFILE.

Thanks
Zeppelin

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