INHERITANCE
1. Copying of one
class properties to another class is called INHERITANCE.
or
It is the concept
of passing the properties of one class to another class.
2. Class which
receives the properties is called CHILD CLASS/SUB CLASS.
3. Class which
passes the properties is called SUPER CLASS.
4. We can use an
existing class to derive a new class; derived class inherits the data and
method of super class.
5. Derived class
can over write the existing method also we can add new code.
6. The main assest
is REUSABILITY.
I.e. we can add additional features to the
existing class without modifying it.
METHOD OVERLOADING
Method are of same
name but different parameters (import/export).
METHOD OVERRIDING
Child class
inherits the super class method s and over writes with some additional functionality
is called method overriding.
REDEFINITION
Nothing but to add
extra logic to the super class method.
It is nothing but
'Method overriding'.
EXAMPLE ON INHERITANCE
Step1
1.
Go to Tcode SE24 and create a super
class.
2.
Create a class as ZCL_SUPERCLASS.
3.We
should remove checkbox FINAL because we need to inherit super class in child
class.
1.
Define method as likp_header_data .
1.
with parameters im_vbeln and ex_likp
1.
Write code as per requirement.
STEP2
1. Create a child class using TCode SE24.
1. Click on save and the super class method LIKP_HEADER_DATA will be
copied automatically.
1. So select our super class method LIKP_HEADER_DATA and click on
REDEFINE ICON to add some extra functionality.
1. Code will be generated automatically then uncomment our code if
needed,
And then write our
extra piece of code as below .
1. And declare ex_lips in Attributes Tab as below.
Save and activate child class.
UING CHILD CLASS IN THE PROGRAM SE38.
OUTPUT:
