I have a class that the user can pass an Action into (or not).
public class FooClass<T> : BaseClass<T>
{
public FooClass()
: this((o) => ()) //This doesn't work...
{
}
public FooClass(Action<T> myAction)
: base(myAction)
{
}
}
Action
. But, at the same time I don't want to force my user to pass in an Action
. Instead, I want to be able to create a "do-nothing" action on the fly.
C programming language is a machine-independent programming language that is mainly used to create many types of applications and operating systems such as Windows, and other complicated programs such as the Oracle database, Git, Python interpreter, and games and is considered a programming foundation in the process of ...
In the real sense it has no meaning or full form. It was developed by Dennis Ritchie and Ken Thompson at AT&T bell Lab. First, they used to call it as B language then later they made some improvement into it and renamed it as C and its superscript as C++ which was invented by Dr.
C is a general-purpose language that most programmers learn before moving on to more complex languages. From Unix and Windows to Tic Tac Toe and Photoshop, several of the most commonly used applications today have been built on C. It is easy to learn because: A simple syntax with only 32 keywords.
What is C? C is a general-purpose programming language created by Dennis Ritchie at the Bell Laboratories in 1972. It is a very popular language, despite being old. C is strongly associated with UNIX, as it was developed to write the UNIX operating system.
You want to say
this(t => { })
Think of it like this. You need t => anonymous-expression-body
. In this case, anonymous-expression-body
is an expression
or a block
. You can't have an empty expression so you can't indicate an empty method body with an expression
. Therefore, you have to use a block
in which case you can say { }
to indicate the a block
has an empty statement-list
and is therefore the empty body.
For details, see the grammar specification, appendix B.
And here's another way to think of it, which is a way that you could use to discover this for yourself. An Action<T>
is a method that takes in a T
and returns void
. You can define an Action<T>
via an non-anonymous method or via an anonymous method. You are trying to figure out how to do it using an anonymous method (or rather, a very special anonymous method, namely a lambda expression). If you wanted to do this via a non-anonymous method you would say
private void MyAction<T>(T t) { }
and then you could say
this(MyAction)
which uses the concept of a method group. But now you want to translate this to a lambda expression. So, let's just take that method body and make it a lambda expression. Therefore, we throw away the private void MyAction<T>(T t)
and replace it with t =>
and copy verbatim the method body { }
.
this(t => { })
Boom.
Shouldn't it be curly brackets?
public FooClass()
: this(o => {})
{
}
Lambda form is (/*paramaters*/) => {/*body*}
Parenthesis around the parameters can be omitted, but Curly braces around the body can be omitted only if it's a single (not empty) statement.
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With