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Antes de mais, vamos definir uma ou duas regras de vocabulário para o artigo: Static - Vou referir-me a esta palavra reservada como a sua tradução literal " Estático". Exemplo: classe estática, método estático... Instance Members   - Esta é uma tradução pobre, eu sei, mas refere-se a membros que apenas estão acessíveis utilizando uma instância de uma determinada classe. Chamar-lhes-ei de membros de instância Isolation Frameworks   - Refiro-me a frameworks que ajudam a criar mocks, fakes e stubs para unit testing . Irei traduzir como Frameworks de Isolamento Em C# 2.0 foi adicionada uma nova funcionalidade denominada por classes e membros estáticos. Quando digo membros refiro-me a métodos, propriedades, eventos, etc. Eu tenho algumas opiniões sobre esta palavra reservada que irei partilhar ao longo do artigo, mas vamos começar por olhar para o que podemos fazer com esta feature . Vejamos este código void Main() { Person p = new Person(); p.Name = ...

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...

It's been a while since i wrote the last post, but i did not forget my purpose of creating a series that shows the evolution of C#. Today i came here to talk about one of the most useful features of C#, even if you dont know you're using it. Let's talk about iterators ! What is an iterator? For those of you who didn't read about the iterator pattern somewhere in the internet or in the "Gang of Four" book, you can read a description  here . The iterator is a class/object/whatever which knows how to traverse a structure. So, if you have a list or collection of objects, an iterator would have the knowledge of how to traverse that collection and access each element that it contains. The iterator is a well known design pattern and is behind many of the wonderful that we have nowadays in .NET (Linq comes to mind). Why is it a feature? Truth be told, an iterator is a concept well known way before .NET even existed. Being an OO Design Pattern, the iterator has...