Final Prepare

Question 1

What is the object-oriented relationship between BufferedReader and Reader?

Answer 1

BufferedReader IS-A Reader

Question 2

class

Answer 2

The blueprint from which individual objects are created

Question 3

Object

Answer 3

The root of the class hierarchy. Every class has the object as a superclass. All objects, including arrays, implement the methods of this class

Question 4

instance variable

Answer 4

Variables within a class but outside any method. These variables are initialized when the class is instantiated.

Instance variables can be accessed from inside any method, constructor or block of that particular class

Question 5

Subclass

Answer 5

Inherits all the public and protected members of its parent, no matter what package the subclass is in.

If the subclass is in the same package as its parent, it also inherits the package-private members of parent

Question 6

Primitive vs reference types

Answer 6

Primitive types are basic types of data

1. byte, short, int, long, float, double, char
2. primitive variables store primitive value

Reference types are instantiable class as well as arrays

1. String, Scanner, Random, Die, int[], String[]
2. Reference variables store addresses

Question 7

Java API

Answer 7

1. A list of all classes that are part of the Java development kit (JDK)
2. Includes all Java packages, classes, and interfaces, along with their methods, fields

Question 8

Package

Answer 8

Basics of inheritance in Java

Question 9

Public

Answer 9

Can be accessed from any other class

Question 10

Private

Answer 10

• The most restrictive access level
• Class and interfaces cannot be private
• Can only access using getter/setter
• A strategy to encapsulate data from the outside world

Question 11

Polymorphism

Answer 11

Deals with how the program decides which methods it should use, depending on what type of thing it has. That is the ability to treat objects of different types in a similar manner.

Question 12

Inheritance

Answer 12

When a ‘class’ derives from an existing ‘class’. For example, say we have a Person class, and when our student class inherits from Person class, meaning that student class carries all the public behavior and attributes that a person has.

Question 13

Interfaces

Answer 13

Used as the parameter type of one or more methods in the class that solve the problem

Question 14

Overloading

Answer 14

Deals with the idea of having two or more methods in the same class with the same name but different arguments

Question 15

Override

Answer 15

A method with same name and same parameter exist in both superclass and subclass. Method override can be used to rewrites the functionality of the method is given by superclass, and customize it for its own usage

Question 16

Static

Answer 16

A member of the class that isn’t associated with an instance of a class. Instead, the member belongs to the class itself. In other words, you don’t need to create an instance in order to use the variable

Question 17

Protocol

Answer 17

• The messages that are understood by the object
• The arguments that these messages may be supplied with
• The types of results that these messages return
• The invariants that are preserved despite modifications to the state of an object
• The exceptional situations that will be required to be handled by clients to the object

Question 18

HTTP

Answer 18

Hyper Text Transfer Protocol, it allows World Wide Web users to transfer information like image, text. It’s used to access HTML pages