Collections Class

Collections Class  in C#

To construct and manipulate a collection of objects, .Net framework has provided us with many classes. ArrayList, BitArray, HashTable, SortedList, Queue and Stack are some of them. They are all included in System.Collections namespace.

ArrayList

The main problem of traditional arrays is that their size is fixed by the number you specify when declaring the array variable: you cannot add items beyond the specified dimension. Another limitation is that you cannot insert an item inside the list. To overcome this, you can create a linked list. Instead of working from scratch, the .NET Framework provides the

ArrayList class.

With the ArrayList class, you can add new items to a list, insert items inside a list, arrange items of a list, check the existence of an item in a list, remove an item from the list, inquire about the list, or destroy the list. These operations are possible through various properties and methods.

Hashtable

The System.Collections namespace provides a Hashtable container. A Hashtable represents a key/value pair in which the key is used for fast lookup.

BitArray

The BitArray class supports a collection of bits which are represented as Booleans. Because it stores bits rather than objects, BitArray has capabilities different from those of the other collections. However it still supports the basic collection underpinning by implementing ICollection and IEnumerable. It also implements ICloneable.