LINQ mind maps
More mind maps which can be useful for .NET learners.
LINQ is an important topic, and understanding its concepts is crucial.
LINQ is built around IEnumerable<T> and IEnumerator<T> interfaces.
It is implemented as extension generic methods which allows us to use it
with all collection classes.
Due to the nature of IEnumerator<T>, LINQ methods returning IEnumerable<T> have a concept of lazy (also called deferred) execution.
All generic methods in C#, including LINQ, can implicitly infer type arguments, thus we do not need to specify them in most cases.
Another important topic in LINQ world is delegates. Delegates are types representing references to methods. Majority of LINQ methods accept Func<...> delegates.
Most common option to provide a delegate is to write a lambda expression (or statement).
It’s important to understand that lambda expressions can capture outer variables (a.k.a. closures).
We also should be aware that if you work with IQueryable<T> interface, the query is compiled (for example in SQL) and executed remotely.
There are methods for filtering, projecting, joining, ordering, grouping, conversion, set operators, element operators, aggregation, quantifiers, and generation.