MSDN / Core Libraries / System.Collections.Generic

System.Collections.Generic

Overview

The System.Collections.Generic namespace contains interfaces and classes that define generic collections, which allow you to create strongly typed collections that provide better type safety and performance than non-generic strongly typed collections.

Common Types

  • List<T> – Represents a strongly typed list of objects that can be accessed by index.
  • Dictionary<TKey,TValue> – Represents a collection of keys and values.
  • Stack<T> – Represents a last-in, first-out collection.
  • Queue<T> – Represents a first-in, first-out collection.
  • HashSet<T> – Represents a set of values.
  • LinkedList<T> – Represents a doubly linked list.

Example: Using List<T>

using System;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        List<int> numbers = new List<int> { 1, 2, 3, 4, 5 };
        numbers.Add(6);
        foreach (int n in numbers)
        {
            Console.WriteLine(n);
        }
    }
}
Imports System
Imports System.Collections.Generic

Module Program
    Sub Main()
        Dim numbers As New List(Of Integer) From {1, 2, 3, 4, 5}
        numbers.Add(6)
        For Each n As Integer In numbers
            Console.WriteLine(n)
        Next
    End Sub
End Module

Related Topics