0-indexing and Visual Basic

[Quimbly]

I come from the C-code world, where everything is 0-indexed: arrays, strings, DB records, etc.

I've seen VB code that starts indexes collection objects from both 0 and 1. Which is it?! Or is it different from object to object?

For instance, the first character in a string object is numbered "1" -- is this correct?

How about for arrays?

What else?!

 

[DrJavaJoe]

An array is zero based
dim MyArray(5) as string
has 6 elements beginning with MyArray(0) to Myarray(5).

In the mid function, that I beleive you are talking about, the second parameter is the starting location in the string. so the first character would be 1. Hope this helps.

"Two strings walk into a bar. The first string says to the bartender: 'Bartender, I'll have a beer. u.5n$x5t?*&4ru!2[sACC~ErJ'. The second string says: 'Pardon my friend, he isn't NULL terminated'."

 

[johnwm]

The default lower bound for an array is zero. You can use the :[tt]

Option Base 1
[/tt]
statement at module level to set all array lower bounds to 1

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[vb5prgrmr]

Arrays can be 0 or 1 based depending upon the coder UNLESS via the split function. Meaning you can have your arrays set to a default of 1 if you wish by including this line "Option Base 1" under the "Option Explicit" line UNLESS an array is specifically dimentioned as variable or zero based...
[tt]
Option Explicit
Option Base 1

Dim Ar1(5) As String 'this array is from 1 to 5
Dim Ar2(0 To 5) As String 'this array is from 0 to 5
Dim Ar3() As String
Dim Ar4(100 To 101) 'contains two elements

Private Sub Form_Load()
Ar3 = Split("This is a test", " ") 'this array will contain elements from 0 to 3
End Sub
[/tt]

Then in general lists are zero based (as in a list boxes list) but items are 1 (as in a collection or a list boxes count property) based no matter what option base you attempt to use.

Good Luck

 

[AndyTWI]

Most prominently as I think of 1-based items right now is the ListView control and Collection objects. Dynamic arrays, listboxes, comboboxes, control arrays are all handled with a base of 0.

If you're not sure, you can open up a blank VB form, drop the desired control onto it and whip up some sample code to test whether or not 0 is the lower boundary by default. You'll get a subscript error if it's not.

 

[JohnYingling]

Get to the .Net Framework where all is 0-based, even the methods of the String Class. VB 1-based string handling is still supported by VB specific statements such as Mid.

http://www.VBResizer.com

Forms/Controls Resizing/Tabbing

http://www.VBCompare.com

Compare Code

http://www.VBSortGen.com

Generate Sort Class in VB

http://www.Vbcompare.com/Check.Htm(1979

Check To MS)