Left fold

Let's talk about accessor's accessibility introduced in C# 2.0. This is a tiny little feature that can make your life easier in a number of ways. But first, let's define what i am talking about. Normally, a property is composed this way: So, from the example above, we can see that a property has a backfield (called _myProperty) and is composed by a getter and a setter . The getter is called whenever you get the value of that property. The setter is called when you set it's value. If we look carefully, we notice that the getter returns the value of the backfield, and the setter sets it's value, respectively. If we think about it, a property is nothing more than a wrapper around a private field. This way we can control all the access to that field's value. C#'s properties are nothing more than sintactic sugar for the following structure: This is an " old school property ". In languages where you don't really have the concept of prop...

In C# 2 there was a new addition in the functionality called static classes and members . When i say "members", i am referring to methods, properties, events and so on. I have a strong opinion about this modifier which i will share with you along the article, but let's start by looking at what "static" means. Take this code as example: Above we can see that we define two properties and one is static. In the main method we then create an instance of Person and set the normal property ( Name ). Now notice the Person.NumberOfBrains  assignment. This is the static property we created in the class. Notice that the access is made at class level , instead of instance level.  This means that there will only be one NumberOfBrains  value throughout all Person instances, but there will be a Name  value per each instance  of Person . Of course, the example is not the best, but you get the idea. Static applies when all  instances share the same value. There are so...

Let's get back to my series on the evolution of the C# language. Everybody is familiar with what a delegate is, right? We know that delegates are a big part of the events system in .Net. We register a method on that delegate ( called handler ) that is invoked when the delegate is invoked. In other words, a delegate simply points to a method. The advantage here is that, as the delegate wraps the method and is an object, we can simply pass it to a method as a parameter! Think about this: This is how we use a delegate in events, for instance. The class exposes the delegate and we register our method to listen it. When the delegate is called inside the class, all the registered methods will be called (because of this, we call it a Multicast Delegate ). This works well, because all you have to do is have a method with the required signature. In the example above, we needed to declare two methods just to make a Console.WriteLine. Isn't this too much? I think it's a bit to...

It's 3 am and i don't feel like sleeping. I've been helping a friend to work on his code and now i'm only partially tired. Well, why not continue with my series on the evolution of C#? Let's do it! So, this time i'm going to talk about nullable types . Everybody used them already, but back in .Net 1.0 they didn't exist. How did you represent a "no value present" value? Sure, string can have null, but null is different than empty, right? How do you represent an empty numeric type then? You check if it is bigger than 0? Well for some cases that's just how developers did it. Either that or create a constant value that represents a "no value". But, to me, that is not expressive enough . Basically, a nullable type is only a non-nullable type wrapped in the System.Nullable struct. This is a generic struct, so it makes use of the Generic features of C# 2.0. The struct is very simple, it contains only a HasValue and a Value proper...

For those of you interested, i found a very interesting list of features that were introduced in C# in  here . This is a very complete list that contains all the features, and i'm explaining them one by one in this post series. We've talked about  Generics  and  Iterators . Now it's time for some partial types . A partial type  is a type which definition is spread across one or more files. It doesn't have to be in multiple separated files, but can be. This is a very simple concept that can give us many benefits, let's see: If a type is partial, multiple developers can work on every part of it. This allows a more organized way of working and can lead to production improvement.  Winforms , for example, generates a partial class for the form so that the client can separately edit other parts it. This way, a part contains information about the design and the other contains the logic of the form. In fact, this is a very spread pattern across .Net. Ent...

This is a well discussed matter throughout the internet. Everyone knows about generics, what they do and what they are used for, right? No. There is a variety of reasons why you wouldn't know about generics, and some of them are: You are new in the language You are not new in the language but never cared to learn it Simply because you never learned the basics about generics, it doesn't mean you've never used it. If you recognize this snippet, then you are already dealing with generics: So, what is the advantage of generics? Type safety Generics will allow you to catch the errors at compile time rather than runtime by enforcing the rules of type safety that make C# a statically typed language. This leads to increased productivity because you don't have to run the code to know that something is wrong. For example, if in the snippet above you tried to add a new item of type string, a compiler exception would be thrown. Typically, in C# 1.0, you would use an...