Linq Interview Question

What are the three main components of LINQ or Language INtegrated Query?

1. Standard Query Operators

2. Language Extensions

3. LINQ Providers

How are Standard Query Operators implemented in LINQ?

Standard Query Operators are implemented as extension methods in .NET Framework. These Standard Query Operators can be used to work with any collection of objects that implements the IEnumerable interface. A class that inherits from the IEnumerable interface must provide an enumerator for iterating over a collection of a specific type. All arrays implement IEnumerable. Also, most of the generic collection classes implement IEnumerable interface.

How are Standard Query Operators useful in LINQ?

Standard Query Operators in LINQ can be used for working with collections for any of the following and more.

1. Get total count of elements in a collection.
2. Order the results of a collection.
3. Grouping.
4. Computing average.
5. Joining two collections based on matching keys.
6. Filter the results


List the important language extensions made in C# to make LINQ a reality?
1. Implicitly Typed Variables
2. Anonymous Types
3. Object Initializers
4. Lambda Expressions