8 Interview Questions in Java to Demonstrate Expert Skill

The class from which the subclass is derived is the superclass. Every class has only one direct superclass.
The extra-terrestrial method happens to be the primary method of program launch in Java. However, similar to other methods, main () can be overloaded. However, when the program is opened while the overload main method is being used, the program will not execute as expected.

Members of the grandparent class cannot be accessed directly in Java, and classes get their object class indirectly or directly. Thus, only one inheritance tree of classes exists in Java, and the root is the object class.
In Java, a distinction is made for keywords used for different classes and abstract functions. A different keyword interface is employed for interfaces in Java. Java does not support multiple inheritances.
Also, Java doesn’t provide a specifier for inheritance as C++ does. Specifiers like protected, private, or public are not attached to a specifier, like is obtainable with C++. In Java, parent classes’ constructor classes are automatically called just like it is in C++. The distinction comes when the parent constructor must be called, as super has to be added to it.

For functions to be overloaded in Java, they have to be different in more than just the return type. This is also the case in C++. The parameters that are used to generate the unique mangled name for different functions are the number of arguments, type of arguments, and the sequence of arguments.

It is impossible to override private methods in Java because they’re hidden and not visible from other classes.

The concept of object cloning in Java is used to create an accurate copy of an original object. However, some interfaces must be implemented and the clone method overridden for a class to support cloning. Thus, the key to avoiding the ‘CloneNotSuportedException’ exception is to ensure that the class of the object about to be cloned can implement a cloneable interface.

In Java, abstract classes are classes that have at least one abstract method in them. An abstract method is one that has no implementation but has been declared. Implementations for abstract methods are done with subclasses as required by abstract classes. Also, in Java, an abstract class usually has constructors that are called when an inherited class is generated.
Abstract classes can also exist without abstract methods in Java. This absence of abstract methods allows the creation of classes that must be inherited and cannot be instantiated. In addition, the abstract classes sometimes have methods that are impossible to override. The methods that can’t be overridden are final methods.

In Java, static methods can be overloaded because more than two methods can be used simultaneously, with the only difference between them being the input parameters.
However, static methods cannot be overridden in Java. This is as a result of the fact that it is only in the context of dynamic that the overriding of methods can occur. In a subclass, static methods that exist with the same signature can be declared, but it is only regarded as overriding when run-time polymorphism occurs.

Objects are stored in memory because there is a dynamic allocation of all objects on Heap. In Java, only a reference is created when a variable of a class type is declared, and memory is not segregated for the new object.