[VB.NET] Arrays

Conrad11 · 9 Oct 2006 at 19:47

Hi there,

I am doing a little VB.NET and was wondering how i can make an array and not set the size and then use a loop to keep adding things too it.

Thanks.

robmiller · 9 Oct 2006 at 20:10

I presume you're using .NET 2.0; if so, use a List. It's in System.Collections.Generic.

Edit: http://msdn2.microsoft.com/en-us/library/6sh2ey19.aspx

TrUz · 9 Oct 2006 at 20:51

As said if you do not know the size then you will be better of with an ArrayList as you can just keep adding to it.

TrUz

Inquisitor · 9 Oct 2006 at 21:51

TrUz said:
As said if you do not know the size then you will be better of with an ArrayList as you can just keep adding to it.

TrUz

List > ArrayList

Conrad11 · 9 Oct 2006 at 22:04

Thanks.

Couple of quick questions:

How do you do a newline in VB.NET and how do you escape a quote in a string so i can have:

Code:

string = "this great string is "stringy" isn't it"

Thanks.

Mr^B · 9 Oct 2006 at 22:36

Like this

Code:

string = "this great string is ""stringy"" isn't it"

And for newline you have a choice:

Code:

Microsoft.VisualBasic.

  ControlChars.Cr [Char]
  ControlChars.Lf [Char]
  ControlChars.CrLf [String]

  Constants.vbCr [String]
  Constants.vbLf [String]
  Constants.vbCrLf [String]

  Chr(13) [Char]
  Chr(10) [Char]

System.

  Environment.NewLine [String]

System.Windows.Forms.

  Keys.Return.ToString (String)
  Keys.LineFeed.ToString (String)
  Chr(Keys.Return) (Char)
  Chr(Keys.LineFeed) (Char)

Inquisitor · 10 Oct 2006 at 00:23

Of the above, Environment.NewLine is probably the best choice; it means that your code will be more easily portable, and run on other platforms properly without too much hassle (although the only other platform for C# at the moment is Mono

). It doesn't matter all that much though, as you're unlikely to want to run a .NET application outside Windows, so platform independence in such a minor issue isn't that important.

Conrad11 · 10 Oct 2006 at 19:42

Thanks.

In vb6 you can set 4 variables the same value by this:

Code:

a, b, c, d = 1

But how would i do this in VB.NET. Is it possible without using 4 different lines.

Thanks.

robmiller · 11 Oct 2006 at 12:36

Conrad11 said:
Thanks.

In vb6 you can set 4 variables the same value by this:

Code:

a, b, c, d = 1

But how would i do this in VB.NET. Is it possible without using 4 different lines.

Thanks.

Code:

a = b = c = d = 1

That's typical of virtually every programming language, I would presume it's the same in VB.NET.

Conrad11 · 11 Oct 2006 at 12:52

Thanks for the reply, but it doesn't appear to work.

happytechie · 11 Oct 2006 at 13:18

Conrad11 said:
Thanks for the reply, but it doesn't appear to work.

what is the assignment operator in VB?????

is it pascalish := ?

or perpaps the assignment a = 2 doesn't evaluate to int 2 and evaluates to true or something odd??

&vbnewline& is the new line operator iirc from a similar thread the other day

Paul

Haircut · 11 Oct 2006 at 13:30

I think you have to use four lines of code to do this in VB.NET

You can't do a = b = c = d = 1 because = is used as both the assignment and comparison operator in VB.NET so in the above usage the compiler gets a bit confused.

So, a = b = c is actually evaluated as a = (b = c) where b = c is a boolean that is true or false depending on whether b or c are the same.

n3crius · 11 Oct 2006 at 13:33

yup use a collection of some sort. probably a generic list.

very powerful.

happytechie · 11 Oct 2006 at 16:45

Haircut said:
I think you have to use four lines of code to do this in VB.NET

You can't do a = b = c = d = 1 because = is used as both the assignment and comparison operator in VB.NET so in the above usage the compiler gets a bit confused.

So, a = b = c is actually evaluated as a = (b = c) where b = c is a boolean that is true or false depending on whether b or c are the same.

so in VB.net a = is the same as an == and an = at the same time :eek:

everytime I hear stuff about this language it gets worse and worse

HT

Haircut · 11 Oct 2006 at 17:03

happytechie said:
so in VB.net a = is the same as an == and an = at the same time

everytime I hear stuff about this language it gets worse and worse

HT

Yep, there is no == in VB.

You would simply use something like

Code:

If Variable = Value Then

What's even better is that logical ANDs and ORs use the same keyword as bitwise ANDs and ORs.

Inquisitor · 11 Oct 2006 at 17:08

This is why I don't like VB

toString · 11 Oct 2006 at 17:10

When you declare multiple values in a single line, you can’t specify default values as you can in C#. However, Visual Basic .NET does allow you to do something you can’t in C#—declare multiple variables of different types in a single line.

Dim Bottom As Integer, FieldName As String

Seems us C#ers are really missing out on that one

........

Una · 11 Oct 2006 at 17:12

Inquisitor said:
List > ArrayList

List = LinkedList?

It depends what operations you are performing on the list, and for example where abouts you are doing your insertions/deletions.