Apsolut Software Interview Questions, Process, and Tips

OOP's concepts refer to the principles of Object-Oriented Programming, including encapsulation, inheritance, polymorphism, and abstraction.

• Encapsulation: Bundling data and methods that operate on the data into a single unit (object)

• Inheritance: Allowing a new class to inherit properties and behavior from an existing class

• Polymorphism: The ability for objects of different classes to respond to the same message in differ...read more

A class is a blueprint for creating objects in object-oriented programming.

• Classes define the properties and behaviors of objects.

• Objects are instances of classes.

• Classes can inherit properties and behaviors from other classes.

• Example: Class 'Car' can have properties like 'color' and behaviors like 'drive'.

A constructor in Java is a special type of method that is used to initialize objects.

• Constructors have the same name as the class they belong to.

• They do not have a return type, not even void.

• They are called automatically when an object is created.

• Example: public class Car { public Car() { // constructor code } }

A singleton class is a class that can only have one instance created throughout the program.

• Singleton classes are often used for logging, caching, database connections, and thread pools.

• They have a private constructor to prevent multiple instances.

• They provide a static method to access the single instance.