Exam Questions and CORRECT Answers
Object-oriented programming (OOP) - CORRECT ANSWER - 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 - CORRECT ANSWER - 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 - CORRECT ANSWER - 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 - CORRECT ANSWER - declared in the class scope
{ } denote a change in scope
What is DBMS? - CORRECT ANSWER - Database Management System
, What is RDBMS? - CORRECT ANSWER - Rational Database Management System -
stores data into tables with columns and rows
Ex. SQL Server
class - CORRECT ANSWER - 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 - CORRECT ANSWER - 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 fields or methods that it inherits.
Interface - CORRECT ANSWER - a description of the actions that an object can do. an
Interface is a description of all functions that an object must have in order to be an "X".
http://images.slideplayer.com/14/4328130/slides/slide_3.jpg
Why use an interface? - CORRECT ANSWER - main use is polymorphism, or the ability
to perform the same operation on a number of different objects.
Package - CORRECT ANSWER - a namespace that organizes a set of related classes and
interfaces. Used to keep things organized by placing related classes and interfaces into packages.
Used in Java in order to prevent naming conflicts.
How to create and use objects - CORRECT ANSWER - You can declare, instantiate using
new keyword, or initialize by using new and calling constructor
You can call object fields using the dot method and calling its functions