Can we override variables in Java?

Variables are not polymorphic in Java; they do not override one another. So, as a variable is not overridden, no run time resolution is done for them, hence in the inheritance chain the variable value of the reference class is used when accessed instead of the object type.

Can you override variable Java?

Variables in Java do not follow polymorphism. Overriding is only applicable to methods but not to variables.

What can we override in Java?

Why is @override used in Java?

The @Override annotation denotes that the child class method overrides the base class method. For two reasons, the @Override annotation is useful. If the annotated method does not actually override anything, the compiler issues a warning. It can help to make the source code more readable.

Why overriding is used in Java?

The benefit of overriding is: ability to define a behavior that's specific to the subclass type, which means a subclass can implement a parent class method based on its requirement. In object-oriented terms, overriding means to override the functionality of an existing method.

Java Tutorials || Java OOPS || Overriding wrt variables || by Durga Sir

Can you override instance or static variables?

No, we cannot override static methods because method overriding is based on dynamic binding at runtime and the static methods are bonded using static binding at compile time.

Can we perform overriding on variables?

Variables are not polymorphic in Java; they do not override one another. So, as a variable is not overridden, no run time resolution is done for them, hence in the inheritance chain the variable value of the reference class is used when accessed instead of the object type.

Can we override static method?

Overloading is the mechanism of binding the method call with the method body dynamically based on the parameters passed to the method call. Static methods are bonded at compile time using static binding. Therefore, we cannot override static methods in Java.

Can we override private method?

No, we cannot override private or static methods in Java. Private methods in Java are not visible to any other class which limits their scope to the class in which they are declared.

Can we override constructor in Java?

It does not have a return type and its name is same as the class name. But, a constructor cannot be overridden. If you try to write a super class's constructor in the sub class compiler treats it as a method and expects a return type and generates a compile time error.

Can we override final method?

Any method that is declared as final in the superclass cannot be overridden by a subclass.

Can we overload main method?

Yes, we can overload the main method in Java, but When we execute the class JVM starts execution with public static void main(String[] args) method.

Can constructor be inherited?

Constructors are not members, so they are not inherited by subclasses, but the constructor of the superclass can be invoked from the subclass.

Can return type change in overriding?

Java version 5.0 onwards it is possible to have different return types for an overriding method in the child class, but the child's return type should be a subtype of the parent's return type. The overriding method becomes variant with respect to return type.

Can we overload final method in Java?

yes overloading final method is possible in java.As final methods are restricted not to override the methods. while overloading argument list must be different type of the overloading method.

Can we override abstract method in Java?

A subclass must override all abstract methods of an abstract class. However, if the subclass is declared abstract, it's not mandatory to override abstract methods.

Can constructor be static or final?

No, a constructor can't be made final. A final method cannot be overridden by any subclasses. As mentioned previously, the final modifier prevents a method from being modified in a subclass.

Can we create immutable class in Java?

Immutable class in java means that once an object is created, we cannot change its content. In Java, all the wrapper classes (like Integer, Boolean, Byte, Short) and String class is immutable. We can create our own immutable class as well.

Can a constructor be abstract?

You can't have an abstract constructor, as abstract means you need to provide the implementation for that at some point of time in your subclass. But you cannot override constructor. There will be no point in having an abstract constructor : Since the constructor needs to be of the same name as of class.

Can we make a class private in Java?

No, we cannot declare a top-level class as private or protected. It can be either public or default (no modifier).

Can we override interface?

No. Interface methods can be implemented. To overload/override a method, that method must be defined first. Interface do not contain method definition.

Can we inherit abstract class?

An abstract class cannot be inherited by structures. It can contains constructors or destructors. It can implement functions with non-Abstract methods.

Can abstract method be static?

If you declare a method in a class abstract to use it, you must override this method in the subclass. But, overriding is not possible with static methods. Therefore, an abstract method cannot be static.

Can we execute class without main method?

Yes, we can execute a java program without a main method by using a static block. Static block in Java is a group of statements that gets executed only once when the class is loaded into the memory by Java ClassLoader, It is also known as a static initialization block.

Can method be declared static?

Static methods

When a method is declared with the static keyword, it is known as the static method. The most common example of a static method is the main( ) method. As discussed above, Any static member can be accessed before any objects of its class are created, and without reference to any object.