You can use the keyword within a method in a derived class
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23/12/2022
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Show Core ConceptsInheritance has the same core concepts in any object-oriented language
Inheritance in JavaUse the keyword extends to declare the derived class// Example 1 public class AAA // AAA is the base class { ... } public class BBB extends AAA // BBB is the derived class { ... } // Example 2 public class Employee {...} // base class public class HourlyEmployee extends Employee { ... } // derived keyword superYou can use super like a function call in a derived class constructor -- invokes the base class constructorsuper(); // invokes base class default constructor super(parameters); // invokes base class constructor with parameters // Example, for a class called HourlyEmployee, derived from Employee public class HourlyEmployee extends Employee { public HourlyEmployee() // default constructor { super(); // invokes Employee() constructor } public HourlyEmployee(double h, double r) { super(h,r); // invokes Employee constructor w/ 2 parameters } // ... more methods and data } // end class HourlyEmployee
The protected modifier
The final modifierUse in Java for a few special inheritence-related purposes:
Other differences
Method OverridingJust like in C++, this is when a derived class has a method with the same prototype as a method in the base class. (The derived class function overrides the base class version, when called for a derived object).Example:
Abstract Classes
Which keyword is used to derive a class from another class?A class can be derived from the base class in Java by using the extends keyword. This keyword is basically used to indicate that a new class is derived from the base class using inheritance.
Which method can be defined in the derived class?A derived class has the ability to redefine, or override, an inherited method, replacing the inherited method by one that is specifically designed for the derived class.
Which keywords is used to derived from parent class?Use Java's extends keyword to derive a child class from a parent class, invoke parent class constructors and methods, override methods, and more. Java supports class reuse through inheritance and composition.
When a class can be derived from another class and use its methods?Definitions: A class that is derived from another class is called a subclass (also a derived class, extended class, or child class). The class from which the subclass is derived is called a superclass (also a base class or a parent class).
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