Added in .NET 1.1


Consider upgrading to System.Collections.Generic.List
Represents a collection of items whose size can be changed dynamically.
These items can have different data types

An arraylist is a combination of an array and a collection.
Unique list of IDs - ArrayList (basically a dynamic single dimensional array)
The ArrayList class fully implements the IList interface with all the familiar methods.
This allows you to work with a set of values as if they were an array and a collection at the same time.
An arraylist has the following functionality:
You can address a value by its index
You can quickly sort and reverse the list
You can search sequentially
You can append elements to the end and insert them in a particular position
You can remove any element
Expands automatically as more elements are added (just like a collection)
Imagine that you need to keep track of various objects but you have no idea how many.
It is difficult to use an array for this purpose because you must declare the size of the array at compile time
The ArrayList is a class designed specifically for this situation
This is an aray whose size is dynamically increased as required.

Does an Element Exist

if (myArrayList.Contains(sElement) == true) 

Converting to a String Array

string[] arValues; 
System.Collections.ArrayList myArrayList;
arValues = (string[])arArrayList.ToArray(GetType(String))


AddAppends an element after the last element in the collection and returns the index where it was inserted.
ClearRemoves all elements from the collection.
ContainsReturns TRUE if an element exists in the collection.
CopyToCopies the elements from the collection to a new one-dimensional array, starting at the specified index in the array.
GetEnumeratorReturns an enumerator to iterate an ArrayList
IndexOfReturns the index of the element in the collection, or -1 if it cannot be found.
InsertInserts an element at the specified index.
RemoveRemoves an element from the collection
RemoveAtRemoves an element at the specified index from the collection
ReverseReverses the order of the elements
SortAlphabetically sorts the elements
ToArrayCopies all the elements to a new one-dimensional array


CapacityProperty contains the number of elements the srray can currently hold.
CountReturns the number of elements in the collection.
IsFixedSizeReturns TRUE if no more elements can be added to the collection.
IsReadOnlyReturns TRUE is the elements cannot be altered.

Generic Version

The generic version of this collection is System.Collections.Generic.List

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