Wipro Apprentice Trainee Interview Questions and Answers

Abstract class is a class that cannot be instantiated and interface is a contract that defines methods.

• Abstract class can have both abstract and non-abstract methods while interface can only have abstract methods.

• A class can implement multiple interfaces but can only inherit from one abstract class.

• Abstract class can have constructors while interface cannot.

• Example of abstract class: Animal (abstract method: makeSound(

Polymorphism is the ability of an object to take on many forms.

• It allows objects of different classes to be treated as if they were objects of the same class.

• It is achieved through method overriding and method overloading.

• Example: A shape class can have multiple subclasses like circle, square, triangle, etc. and all of them can be treated as shapes.

• Example: A method can have different implementations in different class...read more

Stack is a data structure that follows Last In First Out (LIFO) principle. Queue is a data structure that follows First In First Out (FIFO) principle.

• Stack is like a stack of plates, where the last plate added is the first one to be removed.

• Queue is like a queue of people waiting in line, where the first person added is the first one to be served.

• Stack operations: push (add element), pop (remove top element), peek (get...read more

Overriding is a feature in object-oriented programming where a subclass provides its own implementation of a method that is already defined in its superclass.

• Overriding allows a subclass to provide a specific implementation of a method that is already defined in its superclass.

• The method signature (name, parameters, and return type) must be the same in both the superclass and subclass.

• The subclass method must have the ...read more