Can A Final Class Implement An Interface?

Can main method be overloaded?

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 overloaded methods have different return types?

An overloaded method may or may not have different return types. But return type alone is not sufficient for the compiler to determine which method is to be executed at run time. Method Overloading means to have two or more methods with same name in the same class with different arguments.

Can interface inherit abstract class?

An interface can inherit multiple interfaces but cannot inherit a class. An abstract class can inherit a class and multiple interfaces. … An interface can have only public abstract methods. An abstract class has protected and public abstract methods.

How do we prevent a method from being overridden?

How many ways to prevent method overriding in Java?By making method final in the base class.By making a method static in the base class.By making a method private in the base class.

Can I inherit one interface from another interface if yes how if no why?

An interface can extend any number of interfaces but one interface cannot implement another interface, because if any interface is implemented then its methods must be defined and interface never has the definition of any method.

Can an interface be static?

An interface in Java is similar to class but, it contains only abstract methods and fields which are final and static. … You can access static methods using class name without instantiation.

Can an interface extend an abstract class?

Implementation: Abstract class can provide the implementation of interface. Interface can’t provide the implementation of abstract class. … Multiple implementation: An interface can extend another Java interface only, an abstract class can extend another Java class and implement multiple Java interfaces.

Can we write method body in interface?

All methods of an Interface do not contain implementation (method bodies) as of all versions below Java 8. … Interfaces cannot be instantiated, but rather are implemented. A class that implements an interface must implement all of the non-default methods described in the interface, or be an abstract class.

What happens when a class implements an interface?

A class implements an interface, thereby inheriting the abstract methods of the interface. Along with abstract methods, an interface may also contain constants, default methods, static methods, and nested types. Method bodies exist only for default methods and static methods.

Can a final method be overloaded?

private and final methods can be overloaded but they cannot be overridden. It means a class can have more than one private/final methods of same name but a child class cannot override the private/final methods of their base class.

Can we override private and final methods?

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 prevent overriding a method without using the final modifier?

In short, its not possible to override private and static method in Java. That’s all about 3 ways to prevent a method from being overridden in Java. Remember, though syntactically you can use private, static and final modifier to prevent method overriding, but you should always use final modifier to prevent overriding.

Can we change argument list of overridden method?

You can’t change the number of type parameters in the overridden method. As for your case, override clearly fails with the return type. But even if the return types were same, your method still wouldn’t be override equivalent, as you have fewer type parameters in the supposed-to-be overridden method.

How can you prevent method overriding?

3. Which of these keywords can be used to prevent Method overriding? Explanation: To disallow a method from being overridden, specify final as a modifier at the start of its declaration. Methods declared as final cannot be overridden.

Can we declare constructor inside an interface?

No, you cannot have a constructor within an interface in Java. You can have only public, static, final variables and, public, abstract, methods as of Java7.

Can a final class be implemented?

You use the final keyword in a method declaration to indicate that the method cannot be overridden by subclasses. … Note that you can also declare an entire class final. A class that is declared final cannot be subclassed. This is particularly useful, for example, when creating an immutable class like the String class.

Can an interface be final?

If you make an interface final, you cannot implement its methods which defies the very purpose of the interfaces. Therefore, you cannot make an interface final in Java. Still if you try to do so, a compile time exception is generated saying “illegal combination of modifiers − interface and final”.

Can a class inherit an interface?

Interfaces can inherit from one or more interfaces. The derived interface inherits the members from its base interfaces. A class that implements a derived interface must implement all members in the derived interface, including all members of the derived interface’s base interfaces.