Cannot find ArrayList type in System.Collections

Question

I wrote this code private ArrayList articles = new ArrayList(); and it just won't compile. Visual Studio is giving me this error:

The type or namespace name 'ArrayList' could not be found (are you missing a using directive or an assembly reference?)

Yet i made sure to import the System.Collections Namespace. I even tried with

System.Collections.ArrayList articles = new ArrayList();

But no success either. Thanks for any help

System.Collections.ArrayList articles = new System.Collections.ArrayList(); would be the correct Syntax there. However it should have definitely worked if you have included a using statement of the appropriate namespace; only issue then could be that the assembly is not referenced at all in your project. — Bogey
– Bogey, Commented Aug 9, 2016 at 11:36
check here for definition and example msdn.microsoft.com/en-us/library/… — Nkosi
– Nkosi, Commented Aug 9, 2016 at 11:37
Are you using Metro app or UWP ? Then, they are gone. Use List<T> instead. — user6522773
– user6522773, Commented Aug 9, 2016 at 11:38
@MrinalKamboj There is no System.Collections.dll. The namespace "System.Collections" is defined in mscorlib.dll which should be included automatically as far as i know. — Chris Schmitz
– Chris Schmitz, Commented Aug 9, 2016 at 11:39

Mamun · Accepted Answer · 2019-12-11 10:33:30Z

3

I know this is an old post, but this might help someone else. As of 2018 and Visual Studio 2017 you can use ArrayList. They are apart of the System.Collections namespace. All you have to do to use an ArrayList is import that namespace using the following:

Using System.Collections;

After you import this namespace you can use ArrayList, Stacks, Queues, and a few other goodies.

To declare an ArrayList you would use the following syntax

ArrayList variable = new ArrayList();

edited Dec 11, 2019 at 10:33

Mamun

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answered Aug 19, 2018 at 8:54

Mason White

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WillardSolutions · Accepted Answer · 2016-12-23 23:23:34Z

1

List<List Item> list = new List<List Item>();

You can use this code for .net version higher than 4.0. * avoid spaces between List and Item inside <> on both sides...

edited Dec 23, 2016 at 23:23

WillardSolutions

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answered Dec 23, 2016 at 22:47

Vimal Pandey

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Vishal Prajapati · Accepted Answer · 2016-08-11 04:56:01Z

0

If you are using Framework 4.0 or higher Arraylist() is not available.You need to use the available Generic List

answered Aug 11, 2016 at 4:56

Vishal Prajapati

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John Alexiou Over a year ago

Finally they removed ArrayList. (I missed the memo). I am tired of seing "expert" [c#] programmers use ArrayList.

Mrinal Kamboj · Accepted Answer · 2016-08-09 11:43:22Z

-2

System.Collections.ArrayList articles = new System.Collections.ArrayList();

This is correct syntax

edited Aug 9, 2016 at 11:43

Mrinal Kamboj

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answered Aug 9, 2016 at 11:41

W Lojek

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1 Comment

Prince Gnakou Over a year ago

The autocomplete feature doesn't even suggest ArrayList when i type System.Collections.Arr and then it Ctrl + Tab

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