Revature Interview Questions and Correct Answers Object-oriented programming (OOP)

Object-oriented programming (OOP) Ans: a programming language model organized around objects that have data and methods that form the object. It's an instance of a class. four main concepts: 1. Encapsulation 2. Abstraction 3. Inheritance 4. Polymorphism. Variables Ans: A structure for temporarily storing data in your computers memory 1. primitive variables - data types like integers, decimals, and alphanumeric characters 2. reference variables- store memory addresses where objects are located. use a class (name) as their type and can only point to objects that are instances of the class that is their type Arrays Ans: A collection of primitive values or object reference organized with an index. A specific amount of memory is reserved for an array based on the size and data type Instance variable Ans: declared in the class scope { } denote a change in scope What is DBMS? Ans: Database Management System What is RDBMS? Ans: Rational Database Management System - stores data into tables with columns and rows Ex. SQL Server class Ans: a blueprint or prototype from which objects are created. a representation of a type of object. Example: class called Vehicle describes the minimum things that a vehicle is. Inheritance Ans: Inheritance allows a class to use the properties and methods of another class. Allows parent/child relationship. Example: car and truck inherit functions of vehicle but car is not truck or vice versa. A class inherits fields and methods from all its superclasses, whether direct or indirect. A subclass can override methods that it inherits, or it can hide field