Contents
- 1 How does a Java programmer force a method to implemented in a subclass?
- 2 Can we override the protected method of super class as a public method in the sub class?
- 3 Can we override already overridden method in java?
- 4 How to enforce an abstract method in Java?
- 5 How to invoke the superclass constructor in Java?
How does a Java programmer force a method to implemented in a subclass?
4 Answers. You can not force a subclass to override a method. You can only force it to implement a method by making it abstract.
Which method overrides a method in the superclass?
Instance Method
Overriding and Hiding Methods
| Superclass Instance Method | Superclass Static Method | |
|---|---|---|
| Instance Method | Overrides (must also have the same return type) | Generates a compile-time error |
| Static Method | Generates a compile-time error | Hides |
Can we override the protected method of super class as a public method in the sub class?
Yes, the protected method of a superclass can be overridden by a subclass. If the superclass method is protected, the subclass overridden method can have protected or public (but not default or private) which means the subclass overridden method can not have a weaker access specifier.
How do you extend a public class in Java?
The extends keyword extends a class (indicates that a class is inherited from another class). In Java, it is possible to inherit attributes and methods from one class to another. We group the “inheritance concept” into two categories: subclass (child) – the class that inherits from another class.
Can we override already overridden method in java?
Invoking overridden method from sub-class : We can call parent class method in overriding method using super keyword. Overriding and constructor : We can not override constructor as parent and child class can never have constructor with same name(Constructor name must always be same as Class name).
Can you force a subclass to call a super method in Java?
In java, you cannot directly force a subclass to call the super implementation of a method, afaik (see the pattern described in other answers for work-around).
How to enforce an abstract method in Java?
If you want that the subclass of Class A must override the methodA () of Class A, then you have to declare the methodA () as abstract method and Class A is an abstract class. If any class method having some implementation then it will act as a default implementation of the subclasses.
Can a subclass override an abstract class implementation?
Subclasses can optionally override that with their own implementation. If you want to give implementation to the subclass only and force the subclasses to follow a contract (method signature) then this is a clear situation of abstract class.
How to invoke the superclass constructor in Java?
Here is the MountainBike (subclass) constructor that calls the superclass constructor and then adds initialization code of its own: Invocation of a superclass constructor must be the first line in the subclass constructor. With super (), the superclass no-argument constructor is called.