Learn how to leverage LINQ (Language Integrated Query) of C# to sort, filter, group content-items. This demo uses the following data in app:

• Persons - various people who are used in the data. A person can also have one or many favorite books.
• Books - books people wrote or contributed to. Books have authors and

Some notes before we start

All our code uses some general stuff explained here:

• to enable LINQ commands we always need:
  @using System.Linq
• most of the code starts by retrieving a list of Books and Authors. This is done using:
  App.Data["Books"]
• Since we want to use dynamic types (which lets us write things like book.Name, we usually wrap it with:
  AsList(App.Data["Books"])
• The compiler often can't guess object types we are using, we often need to cast lists to:
  IEnumerable<dynamic>
  The easiest way is to just run it through AsList(original as object).
  The as object part necessary because of limitations in Razor.

This filters the authors with long first names.

Count some stuff.