C#-Collections

In the C#, Collection classes serve various purposes, such as allocating memory dynamically to elements and accessing a list of items based on an index, etc. These classes create collections of objects of the Object class, which is the base class for all data types in C#.

• store object
• update object
• delete object
• retrieve object
• search object, and
• sort object

You can store objects in an array or collection. The collection has an advantage over the array. The array has a size limit but objects stored in the collection can grow or shrink dynamically.

Types of Collections in C#

There are 3 ways to work with collections which are given below.

1. System.Collections.Generic classes
2. System.Collections classes (Now deprecated)
3. System.Collections.Concurrent classes

1) System.Collections.Generic classes

• List
• Stack
• Queue
• LinkedList
• HashSet
• SortedSet
• Dictionary
• SortedDictionary
• SortedList

2) System.Collections classes

These classes are legacy. It is suggested now to use System.Collections.Generic classes. The System. Collections namespace has the following classes:

• ArrayList
• Stack
• Queue
• Hashtable

3) System.Collections.Concurrent classes

The System.Collections.Concurrent namespace provides classes for thread-safe operations. Now multiple threads will not create problems for accessing the collection items.

• BlockingCollection
• ConcurrentBag
• ConcurrentStack
• ConcurrentQueue
• ConcurrentDictionary
• Partitioner
• Partitioner
• OrderablePartitioner