Abstract
Class and Abstract Method
Abstract Class:
When we declare a class as abstract,
this class cannot initiate in X++ code. To use this class or its method we have
to first extend this class than only we are able to use this class or its
method. To understand the abstract class consider following example
We have three classes
1. absClass (it’s an abstract class)
2. normalClass
(an another class which will use the absClass methods)
3. extendAbsClass
(this class will extends the absClass)
1. abstract
class absClass
{
}
void printName()
{
; info("AbsClass... Deepak");
}
2. class
extendAbsClass extends absClass
{
}
3. class normalClass
{
}
void accessAbsClass()
{
absClass absClass;
extendAbsClass extendAbsClass;
;
// absClass = new absClass(); // this declaration will throw error “Object could not be created because class absClass is
abstract” so first we extend absClass into extendsAbsClass and further use
extendsAbsClass to access absClass methods.
extendAbsClass = new
extendAbsClass();
extendAbsClass.printName();
}
Abstract Method:
When we declare a method as abstract
, this method should be overload in child class or we can say , this
method should be declare/initiate in
child class, than only we can use this class or its method.
Note:
a. Abstract
methods may only be declared in abstract classes.
b. No code or
declarations are allowed in abstract methods.
We have three classes
i.
absMethodClass
ii.
extendAbsClass
iii.
NormalClass
1. abstract
class absMethodClass
{
}
abstract void absPrintName()
{
//
we cannot declare any code in abstract method
}
2. class
extendAbsClass extends absMethodClass
{
}
void absPrintName()
{
; // we have
to initiate abstract method here as this class extends the abstract class.
info("abstract method declaration in derived class");
}
3. class
childClass_1
{
}
void accessAbsClass()
{
extendAbsClass extendAbsClass;
;
extendAbsClass
= new extendAbsClass();
extendAbsClass.absPrintName();
}
- Harry
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