What will happen if we are not implementation of method in interface?
If you don’t implement all methods of your interface, than you destroy the entire purpose of an interface. We can override all the interface methods in abstract parent class and in child class override those methods only which is required by that particular child class. Define that class as an abstract class.
Is it mandatory to implement all the methods of an interface in ABAP?
A class must implement all methods of the interface in its implementation part, with the following exceptions: Interface methods declared as optional using the addition DEFAULT. Interface methods specified in the class after the addition ABSTRACT METHODS (making them abstract).
What does program to interface, not implementation mean?
Well to find the answer to this question, we need to look at a best practice “Program to an interface, not an implementation”. What this best practice says is that the application should always use interfaces from other part of the application rather than the concrete implementations.
Can a programmer write a program to interface?
Anyone can write code that would make the application to work but the differentiating factor is whether or not this code is maintainable, extensible and testable. Let us try to look at these three concepts in details and understand how programming to an interface is always beneficial.
Which is more flexible implementing interface or program?
Implementing interfaces is more flexible i.e. A class can have only one immediate base class but it can implement more then one interface. Which would mean that our concrete class can adhere to more than one contracts by implementing multiple interfaces.
How is an interface implemented in an abstract class?
An interface could be implemented by a class and also by a structure which is a value type, not a reference type. whereas the abstract class can only be inherited by classes i.e reference type. Polymorphism based on interfaces is more flexible then the one based on the base class.