Namespace: System.Collections

The System.Collections namespace contains interfaces and classes that define various collections of objects, such as lists, queues, bit arrays, hashtables and dictionaries.

Members of System.Collections Namespace

Class	Description
class ArrayList	Implements the IList interface using an array whose size is dynamically increased as required.
class BitArray	Manages a compact array of bit values, which are represented as Booleans, where indicates that the bit is on (1) and indicates the bit is off (0).
class CaseInsensitiveComparer	Compares two objects for equivalence, ignoring the case of strings.
class CaseInsensitiveHashCodeProvider	Supplies a hash code for an object, using a hashing algorithm that ignores the case of strings.
class CollectionBase	Provides the base class for a strongly typed collection.
class Comparer	Compares two objects for equivalence, where string comparisons are case-sensitive.
class DictionaryBase	Provides the base class for a strongly typed collection of key-and-value pairs.
class Hashtable	Represents a collection of key-and-value pairs that are organized based on the hash code of the key.
class Queue	Represents a first-in, first-out collection of objects.
class ReadOnlyCollectionBase	Provides the base class for a strongly typed read-only collection.
class SortedList	Represents a collection of key-and-value pairs that are sorted by the keys and are accessible by key and by index.
class Stack	Represents a simple last-in-first-out collection of objects.

Interface	Description
interface ICollection	Defines size, enumerators and synchronization methods for all collections.
interface IComparer	Exposes a method that compares two objects.
interface IDictionary	Represents a collection of key-and-value pairs.
interface IDictionaryEnumerator	Enumerates the elements of a dictionary.
interface IEnumerable	Exposes the enumerator, which supports a simple iteration over a collection.
interface IEnumerator	Supports a simple iteration over a collection.
interface IHashCodeProvider	Supplies a hash code for an object, using a custom hash function.
interface IList	Represents a collection of objects that can be individually accessed by index.

Structure	Description
structure DictionaryEntry	Defines a dictionary key-and-value pair that can be set or retrieved.

• System.Object
• System.Collections.ArrayList --- System.Collections.IList, System.Collections.ICollection, System.Collections.IEnumerable, System.ICloneable
• System.Collections.BitArray --- System.Collections.ICollection, System.Collections.IEnumerable, System.ICloneable
• System.Collections.CaseInsensitiveComparer --- System.Collections.IComparer
• System.Collections.CaseInsensitiveHashCodeProvider --- System.Collections.IHashCodeProvider
• System.Collections.CollectionBase --- System.Collections.IList, System.Collections.ICollection, System.Collections.IEnumerable
• System.Collections.Comparer --- System.Collections.IComparer
• System.Collections.DictionaryBase --- System.Collections.IDictionary, System.Collections.ICollection, System.Collections.IEnumerable
• System.Collections.Hashtable --- System.Collections.IDictionary, System.Collections.ICollection, System.Collections.IEnumerable, System.Runtime.Serialization.ISerializable, System.Runtime.Serialization.IDeserializationCallback, System.ICloneable
• System.Collections.Queue --- System.Collections.ICollection, System.Collections.IEnumerable, System.ICloneable
• System.Collections.ReadOnlyCollectionBase --- System.Collections.ICollection, System.Collections.IEnumerable
• System.Collections.SortedList --- System.Collections.IDictionary, System.Collections.ICollection, System.Collections.IEnumerable, System.ICloneable
• System.Collections.Stack --- System.Collections.ICollection, System.Collections.IEnumerable, System.ICloneable
• System.ValueType
• System.Collections.DictionaryEntry