What is a delegate in coding?
In object-oriented programming, delegation refers to evaluating a member (property or method) of one object (the receiver) in the context of another original object (the sender).
How do you call a delegate function in C#?
Delegates can be invoke like a normal function or Invoke() method. Multiple methods can be assigned to the delegate using “+” or “+=” operator and removed using “-” or “-=” operator. It is called multicast delegate. If a multicast delegate returns a value then it returns the value from the last assigned target method.
What is a delegate in Java?
Delegation is simply passing a duty off to someone/something else. Delegation can be an alternative to inheritance. Delegation means that you use an object of another class as an instance variable, and forward messages to the instance.
What is the difference between delegate and event?
A delegate specifies a TYPE (such as a class , or an interface does), whereas an event is just a kind of MEMBER (such as fields, properties, etc). And, just like any other kind of member an event also has a type. Yet, in the case of an event, the type of the event must be specified by a delegate.
What is a delegate class?
Delegates are the library class in System namespace. These are the type-safe pointer of any method. Delegates are mainly used in implementing the call-back methods and events. Delegates can be chained together as two or more methods can be called on a single event.
How are delegates used in event handling?
A function that is added to delegates must be compatible with this signature. Delegates can point to either static or instance methods. Once a delegate object has been created, it may dynamically invoke the methods it points to at runtime. Delegates can call methods synchronously and asynchronously.
What are delegates used for?
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. Methods don’t have to match the delegate type exactly.
What is the difference between an interface and a delegate?
Interface calls are faster than delegate calls. An interface reference is a reference to an instance of an object which implements the interface. An interface call is not that different from an ordinary virtual call to an method. A delegate reference, on the other hand, is a reference to a list of method pointers.
How does delegate differ from a event?
What are the special features of delegate?
- Delegates allow methods to be passed as parameters.
- Delegates are type safe function pointer.
- Delegate instances attach or detach a method at run time making it more dynamic and flexible to use.
- Delegates can invoke more than one method using the Multicast feature.
- Delegates are of reference types.