What is the process of defining a method in a subclass having same name and type signature as a method in its superclass in Java?
In any object-oriented programming language, Overriding is a feature that allows a subclass or child class to provide a specific implementation of a method that is already provided by one of its super-classes or parent classes. When a method in a subclass has the same name, same parameters or signature, and same return type(or sub-type) as a method in its super-class, then the method in the subclass is said to override the method in the super-class. Show
Method overriding is one of the way by which java achieve Run Time Polymorphism.The version of a method that is executed will be determined by the object that is used to invoke it. If an object of a parent class is used to invoke the method, then the version in the parent class will be executed, but if an object of the subclass is used to invoke the method, then the version in the child class will be executed. In other words, it is the type of the object being referred to (not the type of the reference variable) that determines which version of an overridden method will be executed. class Parent { void show() { System.out.println("Parent's show()"); } } class Child extends Parent { @Override void show() { System.out.println("Child's show()"); } } class Main { public static void main(String[] args) { Parent obj1 = new Parent(); obj1.show(); Parent obj2 = new Child(); obj2.show(); } } Output: Parent's show() Child's show()Rules for method overriding:
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Why Method Overriding ? As stated earlier, overridden methods allow Java to support run-time polymorphism. Polymorphism is essential to object-oriented programming for one reason: it allows a general class to specify methods that will be common to all of its derivatives while allowing subclasses to define the specific implementation of some or all of those methods. Overridden methods are another way that Java implements the “one interface, multiple methods” aspect of polymorphism. Dynamic Method Dispatch is one of the most powerful mechanisms that object-oriented design brings to bear on code reuse and robustness. The ability to exist code libraries to call methods on instances of new classes without recompiling while maintaining a clean abstract interface is a profoundly powerful tool. Overridden methods allow us to call methods of any of the derived classes without even knowing the type of derived class object. When to apply Method Overriding ?(with example) Overriding and Inheritance : Part of the key to successfully applying polymorphism is understanding that the superclasses and subclasses form a hierarchy which moves from lesser to greater specialization. Used correctly, the superclass provides all elements that a subclass can use directly. It also defines those methods that the derived class must implement on its own. This allows the subclass the flexibility to define its methods, yet still enforces a consistent interface. Thus, by combining inheritance with overridden methods, a superclass can define the general form of the methods that will be used by all of its subclasses. Let’s look at a more practical example that uses method overriding. Consider an employee management software for an organization, let the code has a simple base class Employee, the class has methods like raiseSalary(), transfer(), promote(), .. etc. Different types of employees like Manager, Engineer, ..etc may have their implementations of the methods present in base class Employee. In our complete software, we just need to pass a list of employees everywhere and call appropriate methods without even knowing the type of employee. For example, we can easily raise the salary of all employees by iterating through the list of employees. Every type of employee may have its logic in its class, we don’t need to worry because if raiseSalary() is present for a specific employee type, only that method would be called. class Employee { public static int base = 10000; int salary() { return base; } } class Manager extends Employee { int salary() { return base + 20000; } } class Clerk extends Employee { int salary() { return base + 10000; } } class Main { static void printSalary(Employee e) { System.out.println(e.salary()); } public static void main(String[] args) { Employee obj1 = new Manager(); System.out.print("Manager's salary : "); printSalary(obj1); Employee obj2 = new Clerk(); System.out.print("Clerk's salary : "); printSalary(obj2); } } Output: Manager's salary : 30000 Clerk's salary : 20000Related Article:
This article is contributed by Twinkle Tyagi and Gaurav Miglani. If you like GeeksforGeeks and would like to contribute, you can also write an article using write.geeksforgeeks.org or mail your article to . See your article appearing on the GeeksforGeeks main page and help other Geeks. Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above. What is the process of defining a function in a subclass?The process of defining a method in a subclass having same name & type signature as a method in its superclass is known as?. object-oriented-concepts.. method-overriding.. What is the process of defining more than one method with the same name in a class differentiated by method signature?Explanation: Function overloading is a process of defining more than one method in a class with same name differentiated by function signature i:e return type or parameters type and number.
What is the process of defining a method in terms of itself that is a method that calls itself?Recursion is the process of defining something in terms of itself. It allows us to define method that calls itself repeatedly until it meets some base case condition.
Which of this keyword can be used in a subclass to call the constructor of superclass a Super B This C extent D extends?Easy explanation: None.
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