Which assembly do I need to include for the C# where extension method?

Question

What is the name of the assembly that must be included for the Where extension method? I can't find it's name on google, and apparently it's not one of these:

using System;
using System.Collections.Specialized;
using System.Linq.Expressions;
using System.Collections;
using System.Collections.Generic;

Answer 1

Add a reference to the System.Core assembly to your project, and a using System.Linq statement to your source files.

Please take note that using statements do not import an assembly into your project, it only imports symbols from a specified namespace. In order for a namespace to become available, you must first load the assembly that defines that namespace.

If you're using Microsoft Visual Studio and you want to add an assembly reference to your project, open the Project Explorer panel, right-click on your project and go either to Properties or Add reference....

Answer 2

System.Linq

Should do it.

Answer 3

Remember to include the namespace of the extension method in the usings of the class you want to use the extension method in.