phData Senior Data Engineer Interview Questions and Answers

Encapsulation, Inheritance, Polymorphism, Abstraction are the four pillars of OOPS in Java.

• Encapsulation: Bundling data and methods that operate on the data into a single unit.

• Inheritance: Allows a class to inherit properties and behavior from another class.

• Polymorphism: Ability to present the same interface for different data types.

• Abstraction: Hiding the implementation details and showing only the necessary features.

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 are in.

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

• Constructors are called when an object of a class is created.

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

Single page application is a web application that loads a single HTML page and dynamically updates the content as the user interacts with the app.

• SPA uses AJAX and HTML5 to create fluid and responsive user experience.

• It eliminates the need for page reloading during use, making it faster and more efficient.

• Examples include Gmail, Facebook, and Google Maps.

State management is the process of managing the state of an application, including data flow, user interface updates, and user interactions.

• State management involves storing and updating the state of an application to ensure data consistency.

• It helps in managing user interface updates based on changes in the application state.

• State management is crucial for handling user interactions and maintaining a seamless user exp...read more