System.Collections Namespace

Provides interfaces and classes that define collections of objects, such as lists, queues, arrays, hash tables, and dictionaries. This namespace includes both non-generic collections (like ArrayList and Hashtable) and generic collections (like List<T> and Dictionary<TKey, TValue>).

Interfaces

• Interface

  IEnumerable

  interface IEnumerable

  Represents the enumerator, which supports a simple iteration over a non-generic collection.

• Interface

  ICollection

  interface ICollection

  Represents the root of the non-generic collection hierarchies. Provides the base interface for deriving specialized, domain-specific collection interfaces.

• Interface

  IList

  interface IList

  Represents a non-generic collection of objects that can be individually accessed by index.

• Interface

  IDictionary

  interface IDictionary

  Represents a non-generic collection of key/value pairs.

Classes

• Class

  ArrayList

  class ArrayList : ICollection, IEnumerable, IList

  Represents a non-generic collection of objects that can be individually accessed by index. The size of the ArrayList is automatically increased as elements are added.

• Class

  Stack

  class Stack : ICollection, IEnumerable

  Represents a LIFO (Last-In, First-Out) collection of objects.

• Class

  Queue

  class Queue : ICollection, IEnumerable

  Represents a LIFO (Last-In, First-Out) collection of objects.

• Class

  Hashtable

  class Hashtable : ICollection, IDictionary, IEnumerable

  Represents a collection of key-value pairs that are organized based on the hash code of the key.

Enumerations

• Enum

  CollectionChange

  enum CollectionChange

  Specifies the type of change that occurred in a collection.