Method to check if a collection has any upper case or lower case only - now written also with LINQ

Method to check if a collection has any upper case or lower case only - later this method will be written with LINQ

Adding a new feature of printing to the Console by a new Decorator

Implementing a new class according to a Decorator design pattern in order not to change an existing code

First version of a simple cache

Refactor - filtering strategies are now kept in an IEnumerable interface and a method FilterBy is a generic method, accepting any type of collection

Refactor - moving a filtering strategy to a new class, changing a switch to a Dictionary

Refactor - using Func and lambda expression

Refactor - moving switch statement and filter methods to a class

Strategy Design Pattern - first version of a code

Added some coments to the code

Some advanced use of Dictionary to practice this collection type

Simple refactor of code for basics of dictionaries - in order to keep a List<string> of currencies acceptable in one country

Basics of dictionary

Delegates implemented with simple methods