Add values to string array ?

[Pim75]

Hello,

I'm defining a string array like:
Dim strArray() As String = {"1", "2"}

Can I add some values to this string array later in the code?
It's not clear to me how to do this. I hope someone can help me.

Thanks in advance!

 

[Eliyahu Goldin]

No, you can't. A regular array has fixed size. You can use ArrayList or
other collection types for variable size.

 

[Pim75]

Thanks,
Would it be possible to give a little example of how to fill an
ArrayList and
convert it to a string Array after that?

I need the string Array to call another function.

No, you can't. A regular array has fixed size. You can use ArrayList or
other collection types for variable size.

--
Eliyahu Goldin,
Software Developer & Consultant
Microsoft MVP [ASP.NET]http://msmvps.com/blogs/egoldin

Hello,

I'm defining a string array like:
Dim strArray() As String = {"1", "2"}

Can I add some values to this string array later in the code?
It's not clear to me how to do this. I hope someone can help me.

Thanks in advance!- Tekst uit oorspronkelijk bericht niet weergeven -

- Tekst uit oorspronkelijk bericht weergeven -

 

[David Longnecker]

Here's a quick example. The presentation layer (ASPX page) simply has two
labels on it (lblArrayList and lblStringArray) to verify our output. The
ArrayList is part of the System.Collections namespace, so be sure to add
that in to your project.

// Create ArrayList object.
ArrayList myArrayList = new ArrayList();

// Add values; you can do this anywhere.
myArrayList.Add("Hello!");
myArrayList.Add("Goodbye!");

// Copy ArrayList to an object array.
object[] myStringArray = myArrayList.ToArray();

// Output ArrayList to our label to see the results.
foreach (string item in myArrayList)
{
lblArrayList.Text += item.ToString() + ", ";
}

// Output our array to our label to see the results.
foreach (string item in myStringArray)
{
lblStringArray.Text += item.ToString() + ", ";
}

---
David R. Longnecker
Web Developer
http://blog.tiredstudent.com

Thanks,
Would it be possible to give a little example of how to fill an
ArrayList and
convert it to a string Array after that?
I need the string Array to call another function.

No, you can't. A regular array has fixed size. You can use ArrayList
or other collection types for variable size.

--
Eliyahu Goldin,
Software Developer & Consultant
Microsoft MVP [ASP.NET]http://msmvps.com/blogs/egoldin

Hello,

I'm defining a string array like:
Dim strArray() As String = {"1", "2"}
Can I add some values to this string array later in the code? It's
not clear to me how to do this. I hope someone can help me.

Thanks in advance!- Tekst uit oorspronkelijk bericht niet weergeven
-

- Tekst uit oorspronkelijk bericht weergeven -

 

[Guest]

ReDim Preserve still works in VB.
If you're using 2005, then Array.Resize also works.
But if you're resizing numerous times you may run into performance issues
with either of these approaches since they copy the array on each resize.
Unless you need to use an array, List(Of String) is a better choice in 2005,
or StringCollection in 2003.
--
David Anton
www.tangiblesoftwaresolutions.com
Instant C#: VB to C# converter
Instant VB: C# to VB converter
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[Kris Lankford]

You can not add more items to the array after you have initialized it. What
you could do is this:

C#
--------------------------------------
ArrayList arrStrings = new ArrayList()
arrStrings.Add("1");
arrStrings.Add("2");

//If you need to turn this into an Array after you could just use the
following code

string[] strArray = (string[])arrStrings.ToArray(typeof(string));

//this will le tyou add as many values as you want dynamically and then turn
it back into an array when you are ready
//You could also use the List<T> class instead of the ArrayList class.

I am not sure how this would translate in VB????

Kris

 

[Guest]

See my earlier post. You can certainly add more items to an array in both C#
and VB (using Array.Resize, and additionally ReDim Preserve in VB), but there
may be performance issues if this is done often. In 2005, List(Of String) is
a good alternative.
--
David Anton
www.tangiblesoftwaresolutions.com
Instant C#: VB to C# converter
Instant VB: C# to VB converter
Instant C++: C#/VB to C++ converter
Instant Python: C#/VB to Python converter

You can not add more items to the array after you have initialized it. What
you could do is this:

C#
--------------------------------------
ArrayList arrStrings = new ArrayList()
arrStrings.Add("1");
arrStrings.Add("2");

//If you need to turn this into an Array after you could just use the
following code

string[] strArray = (string[])arrStrings.ToArray(typeof(string));

//this will le tyou add as many values as you want dynamically and then turn
it back into an array when you are ready
//You could also use the List<T> class instead of the ArrayList class.

I am not sure how this would translate in VB????

Kris

Hello,

I'm defining a string array like:
Dim strArray() As String = {"1", "2"}

Can I add some values to this string array later in the code?
It's not clear to me how to do this. I hope someone can help me.

Thanks in advance!

 

[Guest]

See my earlier post. You can certainly add more items to an array in both C#
and VB (using Array.Resize, and additionally ReDim Preserve in VB), but there
may be performance issues if this is done often. In 2005, List(Of String) is
a good alternative.

Well, neither of you are wrong.

Strictly speaking, you can't add items to an array. It's impossible to
change the size of an array once it's created.

What Array.Resize and ReDim does is to create a new array with the
deisred size and copy all the items from the current array.

 

[Guest]

I mentioned that in my first reply. Array.Resize and ReDim Preserve are
useful tools if you must work with a proper array, provided that one is aware
of the copying that is happening behind the scenes on each resize. If
relatively little resizing is done, then there are minimal performance issues.
--
David Anton
www.tangiblesoftwaresolutions.com
Instant C#: VB to C# converter
Instant VB: C# to VB converter
Instant C++: C#/VB to C++ converter
Instant Python: C#/VB to Python converter