Does a subclass must define all the methods from the superclass?
A subclass must define all the methods from the superclass. It is possible for a subclass to define a method with the same name and parameters as a method defined by the superclass. It is possible for a subclass to define a field with the same name as a field defined by the superclass.
Can we define sub class first and super class later in a Java file?
Classes in Java exist in a hierarchy. A class in Java can be declared as a subclass of another class using the extends keyword. A subclass inherits variables and methods from its superclass and can use them as if they were declared within the subclass itself: A subclass can be further subclassed.
How do you call a super class method in subclass?
Subclass methods can call superclass methods if both methods have the same name. From the subclass, reference the method name and superclass name with the @ symbol.
What is method hiding?
Method hiding means subclass has defined a class method with the same signature as a class method in the superclass. In that case the method of superclass is hidden by the subclass. It signifies that : The version of a method that is executed will NOT be determined by the object that is used to invoke it.
What does super () do in Java?
The super() in Java is a reference variable that is used to refer parent class constructors. super can be used to call parent class’ variables and methods. super() can be used to call parent class’ constructors only.
What is super class in Java?
The class from which the subclass is derived is called a superclass (also a base class or a parent class). Excepting Object , which has no superclass, every class has one and only one direct superclass (single inheritance). A subclass inherits all the members (fields, methods, and nested classes) from its superclass.
Why are variables not overridden by a subclass in Java?
Because variables in Java do not follow polymorphism and overriding is only applicable to methods but not to variables. In Java, when the child and parent class both have a variable with the same name, Child class’s variable hides the parent class’s variable, even if their types are different.
How are subclass and Superclass inherited in Java?
Java Inheritance (Subclass and Superclass) 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. superclass (parent) – the class being inherited from.
Is it possible to call sub class methods using super class?
Yes its possible to call sub class methods using super class by type casting to sub class object . By type casting super class object to sub class object we can access all corresponding sub class and all super class methods on that reference. Assigning sub class reference to super class object.
How to reference a subclass in a superclass?
Since the reference ‘mb1’ have access to field ‘seatHeight’, so we print this on console. If there are methods present in super class, but overridden by subclass, and if object of subclass is created, then whatever reference we use (either subclass or superclass), it will always be the overridden method in subclass that will be executed.