Whenever we use the yield keyword in a statement, we indicate that the method, operator, or get accessor in which it appears is an iterator. Of course, since we know that iterators are used to… duh! iterate on collections of data, and since we know that when iterating on a collection, we can use the break keyword to immediately terminate the iteration, it is only obvious that whenever we use an yield return statement to return values in an iterator, like I’ve shown in the previous lesson, we can also use yield break to terminate the iteration of the said iterator.… Read more
Yield break statement
May 11th, 2021Yield return statement
February 22nd, 2021In the previous lesson, I have talked about IEnumerable and IEnumerator, and how they help us when we need to iterate over collections of data. Let’s take an example that deals with those concepts:
We have a function, GenerateRandomNumbers(), inside which we declare a List of ints, generate a number of random ints, equal to the _count parameter, add those random ints to the list, then return the list.… Read more
IEnumerator and IEnumerable
May 8th, 2020Before we can start delving into LINQ, we need to first understand the underlying principles upon which it is built. LINQ is all about operations over collections, so, you’ve guessed it: we will be dealing with collections.
You already learned that of all data structures, arrays are the fastest, because they are unsorted non-generic data structures.… Read more
Extension methods
May 4th, 2020Sometimes, programmers find themselves in need of adding new functionality to already existing codes, in order to improve or complete them. If the said source code is available, the task is simple – they only need to add the required functionality and recompile.… Read more
Delegate covariance and contravariance
March 11th, 2020Let’s talk about something that you should not encounter in your day to day programming experience, but nevertheless, you should be aware of, if you want to become a professional engineer: covariance and contravariance with delegates. They are general programming terms, so, you will encounter them in other programming languages as well, not just C#.… Read more
EventHandler, sender and EventArgs
February 21st, 2020Events Add and Remove
February 19th, 2020In the previous lesson I showed you how the compiler actually implements events by actually adding two methods named addon() and removeon() in the background and making the Action field private, so we can’t invoke it. But that was done in MSIL language, and we really don’t need to deal with such a low level.… Read more
Events
February 5th, 2020Events are a more secure way of implementing the observer pattern described in the previous lesson, and they are the evolutionary step of raw delegates. You may have heard about the event-driven programming as a concept that describes a programming paradigm in which the flow of the program is determined by events such as user actions (mouse clicks, key presses), sensor outputs, or messages from other programs or threads.… Read more
Observer Pattern
February 3rd, 2020According to Microsoft, observer pattern is a behavioral design that allows one object to notify other objects about changes in its state.
Many beginner programmers (and even more experienced ones) have a hard time understanding the link between delegates and events, and the core upon which this link is built is represented precisely by the observer pattern.… Read more
