System.Linq Namespace - .NET API Reference

Namespace: System.Linq

The System.Linq namespace provides classes and interfaces that support queries that use Language-Integrated Query (LINQ).

Classes

Name	Description
Enumerable	Provides a set of static methods for queries that return IEnumerable sequences.
Queryable	Provides a set of static methods for queries that return IQueryable sequences.
ParallelEnumerable	Provides a set of static methods for parallel queries.
Expressions	Contains classes that enable language-level code expressions to be represented as objects in the form of expression trees.

Interfaces

IOrderedEnumerable<TElement>
IGrouping<TKey, TElement>
IQueryable
IQueryable<T>

Sample Code

using System;
using System.Linq;
using System.Collections.Generic;

class Demo
{
    static void Main()
    {
        var numbers = new List<int> { 5, 3, 9, 1, 7 };
        var even = numbers.Where(n => n % 2 == 0);
        var sorted = numbers.OrderBy(n => n);
        Console.WriteLine(string.Join(", ", sorted));
    }
}