Top 40 Sap Object Oriented Abap Interview Questions You Must Prepare 03.Feb.2023

Yes, we can declare events in interface in Object Oriented ABAP

It just like a self­reference, by this we can call methods that are with in same class with out creating object.

Instance method is available separately in each object (instance), static method is global and no instance is required for static method.

  • we cannot create an object to the abstract class instead create an object to the child class and call the methods .
  • Abstract class are mainly used for creating inheritance.

We need to follow below steps when working with events in Object Oriented ABAP:

  • Define an event
  • Define a method
  • Link event and method and convert the method into event-handler method
  • Create a triggering method which will raise the event
  • Use set handler and register event handler method to a particular instance in the program

No it is not mandatory to implement all normal interface methods but it is mandatory to implement all Abstract methods.

Call method ref­>method_name .

We can create many instances of the same class with in a program, but we cannot create many instances of function group.

  • Local classes are defined locally with in a program and the other programs can’t access the same classes directly.
  • But global classes are not like that they are globally accessible from ABAP environment.
  • Global classes are centrally defined in a repository. Transaction code for global classes is SE24(class builder).

No, you can not raise events in interface, Because there is no Implementation for the methods. We can create events in interfaces .

CONSTRUCTOR's are special type of methods, constructor method is executed automatically whenever a object is created or instantiated.

  • Constructor: This method is executed automatically whenever object is created, this is used to set default values with respect to instance/object. The name of the constructor method is CONSTRUCTOR.
  • Static Constructor: This method is executed automatically whenever object is created, this is used to set default values globally irrespective of instances/objects.The name of the static constructor is CLASS_ CONSTRUCTOR.

Class is user defined data type which contains methods, events, attributes, interfaces etc.

Single-ton class is a class which allows to instantiate once only .

Data: ref type ref to .
Create object ref.

Polymorphism is a concept by which the same method names will behave differently in different classes i.e each method will have it's own implementation in different classes but with the same name.

No, we can not instantiate interface using create object keyword.

Global classes and interfaces are defined in the Class Builder (Transaction SE24) in the ABAP Workbench.All of the ABAP programs in an R/3 System can access the global classes

Interface is class which contains methods without implementations.

Friend class is a class it can access private components of it’s friends class.

  • These are special type of methods
  • constructor method is executed automatically whenever a object is created or instantiated
  • These methods are mainly used to set default values in a class
  • The name of the constructor method is 'constructor'
  • These methods have only importing parameters
  • There are no exporting parameters

  • Public class
  • Private class
  • Final class
  • Single­ton class
  • Abstract class
  • Persistent class
  • Friend class

Singleton class is a class which allows to instantiate(Create Object) only once .

 Yes, class can be created without any constructor. Default constructor will be created when we define a class without constructor.

Instead of specifying full name of interface methods, we can assign it a name which can directly trigger.

Abstract methods is a method which doesn't contain any implementation.

Some of the main advantages of Object Oriented ALV

  • We have no of events available in the classes when compared to ALV with function modules which gives flexibility for the programmer to develop ALV'S for various scenarios.
  • We can display more than one ALV grid data on a single screen.
  • The ALV grid data is displayed in the form of custom container with which we can control the size of ALV grid Whereas we cannot control the size of the ALV with function Modules.
  • We can also place different UI elements like checkbox, Radiobutton on the same screen in addition ALV grid data.

Public attributes can be accessed by class, subclasses and other classes where as Private attributes can be accessed by class itself only.

class <cl_name> definition.
Public section.
Methods: m1 importing p1 type <c>
Exporting p2 type <i>
Changing p3 type <n>
Returning p4 type <i>
Exceptions <e1>.
Protected section.
Private section.
Endclass.
Class <c1_name> implementation.
Method m1.­­­­­­
Endmethod.
Endclass

No we can not make interface methods as abstract or final in Object Oriented ABAP

Event is a mechanism by which method of one class can raise method of another class, without the hazard of instantiating that class.

Yes, by using interface concept in SAP ABAP, we can polymorphism

Local classes are defined in an ABAP program (Transaction SE38) and can only be used in the program in which they are defined.

Abstract class is a class which contains at least one abstract method( Method without implementation), Abstract class contains methods with implementation and without implementation and we cannot create instance for the abstract class .

  • Abstract class is mainly for inheritance .
  • Interface contains methods without implementation .

Yes, by using interface concept in SAP ABAp, we can achieve multiple inheritance

Before going to static classes, you should understand static components.

  • Static Components: Static components (static attributes, static events and static methods) exists globally, no need to create object/instance of the class to access them, we can access them by using static component selector => .
  • Static Class: A class that only contains static components and no instance components is referred to as a static class.
  • Singleton Class: It is a class which does not allow you to create multiple instances.

  • It is a class which contains methods with implementation as well as methods without implementation .
  • Abstract class is a class which contains at least one abstract method.

It is the keyword which indicates the class definition is delayed or postponed or Defined at some place in program.

Syntax : CLASSÂ Â DEFINITION DEFERED.

Alias is an alias name for the interface method implemented in the class .

In general we can not create object for a private class, but we can access static method of a private class so call that method using its class name and import that object.

For example take one static method with an exporting parameter inside private class and write object creation code in that static method and export that object.