System.Collections.Generic Namespace

This namespace contains interfaces and classes that define generic collections that can hold value types or object types. Generic collections provide a way to create collection classes that can store any type of data and that can be easily customized. This helps you to avoid type-related errors and improve performance.

Classes

Dictionary<TKey, TValue>

Class

Represents a collection of key/value pairs that are sorted by key. Each element in the dictionary is a structure that contains a value and a key.


public class Dictionary<TKey, TValue> : IDictionary<TKey, TValue>, ICollection<KeyValuePair<TKey, TValue>>, IEnumerable<KeyValuePair<TKey, TValue>>, IDictionary, ICollection, IEnumerable

List<T>

Class

Represents a strongly typed list of objects that can be accessed by index. Provides methods for creating, searching, and manipulating lists.


public class List<T> : IList<T>, ICollection<T>, IEnumerable<T>, IList, ICollection, IEnumerable

Queue<T>

Class

Represents a collection of objects that are accessed in the first-in, first-out (FIFO) order. You can add elements to the end of the queue and remove them from the beginning.


public class Queue<T> : ICollection<T>, IEnumerable<T>, ICollection, IEnumerable

Stack<T>

Class

Represents a collection of objects that are accessed in the last-in, first-out (LIFO) order. You can add elements to the end of the stack and remove them from the same end.


public class Stack<T> : ICollection<T>, IEnumerable<T>, ICollection, IEnumerable

HashSet<T>

Class

Represents a collection of elements that uses hashing for efficient lookups. No duplicate elements are allowed.


public class HashSet<T> : ICollection<T>, IEnumerable<T>, ICollection, IEnumerable, ISet<T>

Interfaces

ICollection<T>

Interface

Represents a strongly typed collection of objects.


public interface ICollection<T> : IEnumerable<T>, IEnumerable

IEnumerable<T>

Interface

Exposes an enumerator, which iterates through the collection.


public interface IEnumerable<out T> : IEnumerable

IDictionary<TKey, TValue>

Interface

Represents a strongly typed collection of key/value pairs.


public interface IDictionary<TKey, TValue> : ICollection<KeyValuePair<TKey, TValue>>, IEnumerable<KeyValuePair<TKey, TValue>>, IEnumerable

IList<T>

Interface

Represents a strongly typed list of objects that can be accessed by index.


public interface IList<T> : ICollection<T>, IEnumerable<T>, IEnumerable