DIM array

[krovit]

Have patience, please...
I am seriously worried: could I have forgotten things I know I already know? Old age?

When sizing or resizing an array, you assign a space to the variables.
The space, at the beginning, is obviously empty (the variables are zeo or null).

Question: is there any way to know if any of the indexed variables has a value different from zeo or different from null?

[krovit]

Excuse me... of course my question refers to a possible alternative of a FOR-NEXT that scans the whole array

[SMcNeill]

Sorry.  I think a FOR.. NEXT loop would probably be your best way to check for the existence of non-zero values. 

[bplus]

Hi krovit,

Here is my test:

Code: QB64: [Select]

1. REDIM arr$(1 TO 10)
2. i = 1
3. WHILE i <= 10
4.     arr$(i) = CHR$(i + 32)
5.     PRINT arr$(i); "  ";
6.     i = i + 1
7. WEND
8. PRINT: PRINT
9. REDIM _PRESERVE arr$(1 TO 20)
10. i = 1
11. WHILE i <= 20
12.     PRINT arr$(i); "  ";
13.     i = i + 1
14. WEND
15. PRINT:: PRINT: PRINT "Now try Type:" 'sometimes Type makes up stuff
16. TYPE xy
17.     x AS STRING
18.     y AS STRING
19. END TYPE
20.  
21. REDIM arr(1 TO 10) AS xy
22. i = 1
23. WHILE i <= 10
24.     arr(i).x = CHR$(i + 32)
25.     PRINT arr(i).x; ","; arr(i).y; "  ";
26.     i = i + 1
27. WEND
28. PRINT: PRINT
29. REDIM _PRESERVE arr(1 TO 20) AS xy
30. i = 1
31. WHILE i <= 20
32.     PRINT arr(i).x; ","; arr(i).y; "  ";
33.     i = i + 1
34. WEND
35.  
36.  

EDIT for strings, well today I couldn't get garbage in unassigned values, 0's or nothings here but as I recall this is not always the case.

[krovit]

Thank you bplus!