2026 QUESTIONS WITH SOLUTIONS GRADED
A+
◉ Variables. 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. 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. Answer: declared in the class scope
{ } denote a change in scope
,◉ What is DBMS?. Answer: Database Management System
◉ What is RDBMS?. Answer: Rational Database Management System -
stores data into tables with columns and rows
Ex. SQL Server
◉ class. 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. 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. 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?. Answer: main use is polymorphism, or the
ability to perform the same operation on a number of different objects.
◉ Package. 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. 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
◉ Encapsulation. Answer: the principle of information hiding and
wrapping code together into a single unit. data is not accessed directly
◉ API. Answer: Application Programming Interface - Contains the
complete listing for all packages, interfaces, classes, fields, and methods
supplied by the Java SE platform
◉ Association. Answer: a relationship between two classes. there is no
owner between objects. For example, a teacher *has-a* or *teaches* a
student. There is no ownership between the teacher and the student