Constructors in OOPS ABAP

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Hey Everyone if you are looking for Constructors in ABAP | Constructors OOPs Notes | Constructors OOPs ABAP Notes | Constructors Notes for Beginner In SAP ABAP then you will get Ideas here.

  • Constructor is a special type of method which is executed automatically when a object is created.
  • They can not be called using the CALL METHOD statement.
  • Constructors are methods with a predefined name.
  • Multiple CONSTRUCTOR and CLASS_CONSTRUCTOR are not allowed with in a class.

Note – Open any class in SE24Class Builder ) transaction code.

  • We can see there are basically two types of Constructors.
  • Click on both the constructors.
  • It will be added automatically into your method section.
  • We can see, now both the constructors are not available on the top right section indicating that, we cannot have Multiple Constructor and Class Constructors at the same time.
  • letʼs differentiate both of them.

Types of Constructors

Constructor ( Instance Constructor ) :-

It has only importing parameters.

Select Instance Constructor and click on parameters.

In the above diagram we can clearly see that we can only have importing parameters for Instance constructors.

It can access both static and Instance attributes.

It is called every time when a object is created.

Used to set default value for a particular instance.

CLASS_CONSTRUCTOR ( Static Constructor )

Name of the method  CLASS_CONSTRUCTOR

It does not have any parameters.

Select the class constructor we and click on parameters.

We will get a notification message that we cannot have any parameters for our class constructor.

It can access only static attributes.

It is called first time when a object is created.

letʼs have some implementation for both these methods so that we can understand it more clearly.

Step 1  Click on the attributes tab and letʼs create two instance attributes and
one static attributes.

Step 2  now click on the source code of instance constructor

Step 3  Now go to the source code of CLASS_CONSTRUCTOR.

As soon as I am trying to access the instance attributes inside a class constructor, We will get a error message.

now, you can see it is working perfectly fine.

Step 4 Go to ABAP Editor  SE38 and create object for our class.

Executing the program

Press F8 to execute the program.

Now, letʼs see and analysis

We can see clearly that our Class constructor executed before the Instance constructor and it gets executed only once.

However our instance constructor will be executed every time when we will create any object.

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