Linq

LINQ to Objects:

01: Simple example of selecting and sorting (from, where, orderby, select).
02: Select by value (from, where, select).
03: Complex filter (from, where, select).
04: Get collection with names of the objects from list (from, select).
05: Creating new object (from, select new).
06: Creating a temp var (from, let, select).
07: Selection from two sources (from, select).
08: Sorting by few parameters (from, orderby, select).
09: Operations on sets (Except, Intersect, Union, Concat, Distinct).
10: Aggregate operations on sets (Aggregate, Sum, Min, Average, Max).
11: Skiping and Taking elemenets in sets (Skip, Take, SkipWhile, TakeWhile).
12: Group list by some value (from, group by, into, select).
13: Union the objects by value and a simple union (join, Join, GroupJoin, Zip).
14: Methods: All, Any (All, Any).
15: Parallelizing work on the collection (AsParallel, ForAll).
16: Parallelizing and sorting work on the collection (AsParallel, AsOrdered).
17: Exception and Cancellation Token (AsParallel, WithCancellation).

18: First introducing in Linq to Xml (XDocument, XElement, XAttribute, XDeclaration, XDocumentType, XProcessingInstruction, Save, Load, Parse).
19: Reading a Xml (FirstNode, LastNode, NextNode, PreviousNode, Nodes, Ancestors, Descendants, NodesAfterSelf/NodesBeforeSelf).
20: Editing a Xml (Add, Remove, SetElementValue).
21: Example of using annotations (AddAnnotation).
22: Complicated query and example of methods: Descendants, Ancestors (Parse, Descendants, Ancestors).
23: Validation document (Validate).