Inheritance Adjustment in System Design: Tailoring Base Class Characteristics for Specialized Classes
Need for Inheritance Adjustment in System Design:
Inheritance Adjustment in system design refers to the process of refining or modifying the inherited characteristics (attributes and behaviors) of a base class to better suit the requirements of a specific derived class. The need for inheritance adjustment arises due to the following reasons:
Specialization:
- Reason: Derived classes may have specialized requirements or additional features that are not present in the base class.
- Example: In a system representing various vehicles, a base class
Vehicle
might have attributes likespeed
andcapacity
. The derived classCar
could specialize by adding attributes likenumberOfDoors
and methods likeaccelerate
.
Restriction:
- Reason: Sometimes, it is necessary to restrict or limit the access to certain features inherited from the base class.
- Example: Consider a base class
Employee
with a methodcalculateSalary
. In the derived classIntern
, thecalculateSalary
method might be adjusted to restrict access or override it with a different implementation.
Inheritance Adjustment Process:
Method Overriding:
- Description: Inheritance adjustment often involves overriding methods inherited from the base class in the derived class.
- Example: In the base class
Animal
, there might be a methodmakeSound()
. In the derived classCat
, themakeSound()
method can be overridden to produce a specific cat sound.
Adding New Attributes or Methods:
- Description: Derived classes may need additional attributes or methods that are not present in the base class.
- Example: If a base class
Shape
has attributes likewidth
andheight
, a derived classCircle
might need to add a new attributeradius
and a methodcalculateArea
specific to circles.
Access Control Adjustment:
- Description: Adjusting access modifiers to control the visibility of attributes or methods inherited from the base class.
- Example: If a base class has a protected method, a derived class might adjust the access control to make it private or public based on the specific requirements.
Example:
Consider a simplified example of a base class Person
in a system, and a derived class Student
that requires adjustment:
class Person:
def __init__(self, name, age):
self.name = name
self.age = age
def displayDetails(self):
print(f"Name: {self.name}, Age: {self.age}")
class Student(Person):
def __init__(self, name, age, studentID):
# Adjusting the constructor by calling the base class constructor
super().__init__(name, age)
self.studentID = studentID
# Adjusting the method to include student-specific details
def displayDetails(self):
super().displayDetails()
print(f"Student ID: {self.studentID}")
# Example Usage:
person = Person("John Doe", 25)
person.displayDetails()
print("\n")
student = Student("Alice Smith", 20, "S12345")
student.displayDetails()
In this example, the Student
class adjusts the inheritance by calling the base class constructor using super()
and overriding the displayDetails
method to include student-specific details. This demonstrates the need for and implementation of inheritance adjustment in system design.