What is a delegate void?
public delegate void Del(string message); A delegate object is normally constructed by providing the name of the method the delegate will wrap, or with a lambda expression. Once a delegate is instantiated, a method call made to the delegate will be passed by the delegate to that method.
Can a func return void?
All Func delegates return something; all the Action delegates return void. There’s also Func and Action (and others up to 16 arguments).
What is func delegate?
Func is a delegate that points to a method that accepts one or more arguments and returns a value. Action is a delegate that points to a method which in turn accepts one or more arguments but returns no value. In other words, you should use Action when your delegate points to a method that returns void.
Why do we use delegates?
Delegates have the following properties:
- Delegates are similar to C++ function pointers, but are type safe.
- Delegates allow methods to be passed as parameters.
- Delegates can be used to define callback methods.
- Delegates can be chained together; for example, multiple methods can be called on a single event.
What is JavaScript void function?
When a function is void, it means that the function returns nothing. This is similar to functions in JavaScript which return undefined explicitly, like so: function und() { return undefined } und()
Is action a delegate?
Action is a delegate type defined in the System namespace. In other words, an Action delegate can be used with a method that has a void return type.
What is func and predicate?
Func is a delegate (pointer) to a method, that takes zero, one or more input parameters, and returns a value (or reference). Predicate is a special kind of Func often used for comparisons (takes a generic parameter and returns bool).
What is action Func and predicate?
Action takes zero, one or more input parameters, but does not return anything. Predicate is a special kind of Func. It represents a method that contains a set of criteria mostly defined inside an if condition and checks whether the passed parameter meets those criteria or not.
Are there any func delegates that return void?
All of the Func delegates return a value. What are the .NET delegates that can be used with methods that return void? All Func delegates return something; all the Action delegates return void. There’s also Func and Action (and others up to 16 arguments).
Which is the last parameter of the func delegate?
The last parameter of the Func delegate is the out parameter which is considered as return type and used for the result. Func is generally used for those methods which are going to return a value, or in other words, Func delegate is used for value returning methods.
How to assign an anonymous method to a func delegate?
You can assign an anonymous method to the Func delegate by using the delegate keyword. A Func delegate can also be used with a lambda expression, as shown below: Func is built-in delegate type. Func delegate type must return a value. Func delegate type can have zero to 16 input parameters.
Can a func delegate be used with a lambda expression?
A Func delegate can also be used with a lambda expression, as shown below: Func is built-in delegate type. Func delegate type must return a value. Func delegate type can have zero to 16 input parameters. Func delegate does not allow ref and out parameters. Func delegate type can be used with an anonymous method or lambda expression.