Object Oriented ABAP Interview Questions Answers
These OOPS ABAP interview questions are frequently asked in the interviews. Just have a look into this post and read this questions. Click on read more to read this post.
SAP OOABAP Interview Questions Answers
OOPS ABAP Interview Questions Answers
1. Explain about Object oriented programming?
Object oriented programming is one of the
most popular methodologies in software development. It offers a powerful model
for creating computer programs. It speeds the program development process,
improves maintenance and enhances re-usability of programs.
- Object
oriented Concepts?
Encapsulation:
It means combining data and
code that acts up on data into one single unit of organization, so that both
are safe from out side interference. In OOAbap encapsulation is achieved
through classes.
Polymorphism:
It means many forms that mean
the same method behaves differently in different method calls.
Inheritance:
It means deriving a child
class from base class; child class acquires all the properties from base class.
Abstraction:
Abstraction simplifies a
complex problem to a simpler problem by specifying and modeling the class to
the relevant problem scenario.
It simplifies the problem by giving the class
its specific class of inheritance. Composition also helps in solving the
problem to an extent.
- What is a
class?
Classes are templates for objects.
Conversely, you can say that the type of an object is the same as its class. A
class is an abstract description of an object.
You could say that it is a set
of instructions for building an object. The attributes of objects are defined
by the components of the class, which describe the state and behavior of
objects.
- What is an
object?
An object is a combination of messages and
data. Objects can receive and send messages and use messages to interact with
each other. The messages contain information that is to be passed to the
recipient object.
- How many types
of classes are there in OOAbap?
Public class
Private class
Final class
Single-ton class
Abstract class
Persistent class
Friend class
- What is the
difference between function group and classes?
We can create many instances of the same
class with in a program, but we cannot create many instances of function group.
- What are the
differences local & global classes?
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).
- What are the
Components of a class?
Attributes and methods are components
inside a class.
- How to define a class locally?
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.
- What is a
constructor & types of constructors?
Constructor is a special method, which will
be called automatically as and when the object is created for a class, it can
have only importing parameters but not exporting, it is generally used to give
some initial state to the object.
A class can contain have two types of
constructors static and instance constructors.
- Difference
between static and instance constructors?
Static constructor will be called only
once, i.e. at the time of loading class in to memory. Instance constructors are
instance specific, these constructors will be called as and when the new object
is created for that class.
- How to a
create object for the class?
Data: ref type ref to <cl_name>.
Create object ref.
- how to call a
method?
Call method ref->method_name
<exporting x = 1>.
- What is static
attribute & method?
Static attributes & methods
are class specific, memory will be allocated only once for Static attributes
& methods irrespective of no. of objects created.
We can access the
components with a reference variable i.e. by using class name
Call method
<cl_name>=>menthod_name.
- Can we instantiate a class within implementation of other class? Yes
- Can we put non
declarative statement e.g. START-OF-SELECTION within a class?
No, we can’t use.
- How to create
a global class?
With tcode SE24
- How can we
pass importing parameter?
Pass by value/pass by reference
- Can we pass returning
parameter by reference? NO only pass by value
- Can a method
call itself? Yes
- What is me
variable?
It just like a self-reference, by this we
can call methods that are with in same class with out creating object.
- Can we have export parameter in Instance constructor? No
- What is an abstract class?
Abstract class contains both abstract
methods and normal methods, abstract methods cannot implement in side abstract
class, and instead these methods will be implemented by child classes of that
abstract class.
- What is final
class & Method?
Final classes can’t be inherited that means
it can not have child classes and final method of a class cannot be redefined.
- What is an
interface?
Interfaces contain only public methods with
no implementation; these interfaces are included in public section of classes
and implement the methods of interfaces.
- Can we implement interface in private section of any class? No
- What is alias?
Instead of specifying full name of
interface methods, we can assign it a name which can directly trigger.
- What is a
friend class?
Friend class is a class it can access
private components of it’s friends class.
- How to create
an object for private 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.
- What is a
Single-ton class?
Single-ton classes can be instantiated only
once, i.e. only one object is created for Single-ton classes.
- What is a
Persistent class?
A special class, the attributes of which are linked to database tables via
object-relational mapping. Since Release 6.10 they can be created using the
Mapping Assistant of the Class Builder.
The objects of persistent
classes are managed by Object Services.
An object in a persistent class, the attributes of which are saved as database
content after the run time of an ABAP program.
Dear Friends if you have any questions on Object Orientation please write in comment box below it'll help fellow ABAPers.
"You found the information helpful and want to say thanks? Your donation is enough to inspire us to do more. Thanks a bunch!"
Posted in: ABAP Interview Questions, ABAP-Interview-Questions, Data-Dictionary, Module-Pool-Programming, Object Oriented ABAP, Object Oriented ABAP Interview Questions, object-oriented-abap, Object-Oriented-ABAP-Interview-Questions, OOABAP, SAP ABAP Interview Questions, SAP ABAP Introduction, SAP Basics, SAP-Enhancements, SAP-Exits
2 comments:
Very Useful information. Commented by Bukkas
how can we differentiate ooabap with core abap? explain in detail.
Post a Comment
Note: Only a member of this blog may post a comment.