What is Super Class in Java?
Introduction
In object-oriented programming (OOP), a super class is a class that contains one or more super classes. It is the parent class that defines the properties and behavior of its subclasses. In Java, the super class is also known as the parent class or parent.
Defining Super Class
A super class is defined using the extends keyword, which indicates that it is the parent class. The class should also declare its name, package, and body.
public class SuperClass {
// Body of the super class
}Subclasses
Subclasses are classes that inherit properties and behavior from the super class. The class should also declare its name, package, and body.
public class Subclass extends SuperClass {
// Body of the subclass
}Inheritance
Inheritance is the process of creating a new class based on an existing class. The new class inherits all the properties and behavior of the existing class and can also add new properties and behavior or override the existing properties and behavior.
Benefits of Inheritance
- Code Reusability: Inheritance allows developers to create a new class based on an existing class, which reduces code duplication and makes it easier to maintain.
- Easier Maintenance: Inheritance makes it easier to modify the existing class without affecting the subclasses.
- Enhanced Cohesion: Inheritance ensures that related classes have a clear relationship and are easier to maintain.
Composition vs Inheritance
Inheritance is a composition-based approach, where a class can contain one or more other classes. This approach allows developers to create complex objects by combining the properties and behavior of smaller classes.
public class Component {
// Properties and behavior of the component
}
public class System {
private Component component;
// Methods and behavior of the system
}Contravention of Inheritance
In Java, it is possible to create a subclass that overrides the constructor of its parent class. This is known as a contravention of inheritance.
public class Contravention extends SuperClass {
public Contravention() {
super(); // Contravention of inheritance
}
}Retainers and Extenders
Retainers and extenders are a set of methods in Java that allow developers to customize the behavior of the super class. Retainers are used to customize the properties and behavior of the super class, while extenders are used to create a subclass that inherits the properties and behavior of the super class.
public class Retainer {
// Properties and behavior of the retainer
}
public class Extend extends SuperClass {
// Methods and behavior of the extend
}Table of Contents
- Introduction
- Defining Super Class
- Subclasses
- Inheritance
- Composition vs Inheritance
- Contravention of Inheritance
- Retainers and Extenders
- Example Use Case
- Conclusion
Conclusion
In conclusion, the super class is a fundamental concept in Java that allows developers to create a new class based on an existing class. It provides a way to inherit properties and behavior from the existing class and can also add new properties and behavior or override the existing properties and behavior. Understanding the super class is essential for developing efficient, maintainable, and scalable software systems.