OOP Fundamentals Pt 1

abstraction, polymorphism, inheritance, encapsulation

4 fundamental concepts of oop (a-pie)

abstracting

when we put a piece of code in a java method, we are ______ the piece of code

implemented

the method’s name can be considered a new concept; we won’t need to know how the method was ______ when reusing it

name, arguments, return values

a method’s interface includes what?

true

T/F: abstractions can have different methods

pure methods

methods that don’t call other methods

first

pure methods belong to the ____ level of abstraction

second

a method that calls other methods belongs at least to the ____ level of abstraction

abstraction

the ability to separate the interface from the implementation

readability, usability, reusability, maintainability

abstraction benefits

higher ____, ____, ____, ____

simplifies, unnecessary 

abstraction ___ complex system by hiding ____ details

method, class, package

abstraction levels

1. putting code in a ____

2. putting several methods in a ____

3. putting classes in a _____

true

T/F: inheritance is a two-way ability

is-a

inheritance is an ____ relationship

child, defines, capabilities

1. The ability of extending a parent class' capabilities by creating a ___ class that gets all parent's capabilities and possibly ______ more.

2. The ability of factoring out the common _____ of a group of classes (children) into a parent class.

parent-chlid

the term______ is more common in database than superclass-subclass

object

every Java class inherits from a parent class called _____

parent

more generalized and is called “superclass”

class

more specific and is called “subclass”

inherited, class member

constructors cannot be _____ because it’s not a _____

overriding

re-implementing an inherited method in the subclass

extends

Java uses the ____ keyword to denote inheritance

asymmetric

inheritance is an ____ relationship (every child is a parent but not the other way around)

inherits

ClassA _____ from ClassB

true

T/F: in a UML diagram, the child class only shows the non-inherited (new) methods

+

which sign stands for the public?

-

which sign stands for private?

#

which sign stands for protected?

~

which sign stands for package private?

visible

all ____ member of superclass are inherited by _____

true, bad

T/F: we can declare the same instance variable name of superclass in subclass. However, this is ___ practice.

super(…)

____ must be the first statement of the subclass constructor

zero-parameter constructor

if you don’t any superclass’ constructor, then by default the  ____ of the superclass will be called

T/F: if you don’t have any constructor in your class, Jaa creates a zero-parameter constructor for you

aren’t, special

constructors ____class members, that’s why we need a ___ way to call it from subclass

this

inside a class, we can invoke its members by using the keyword _______

super

use the ____ keyword when we invoke a superclass method

optional

if a method is not overridden, using the super keyword is ____ (but it’s good programming practice)

multiple inheritance

to have two or more direct superclasses

isn’t, increases

multiple inheritance ____ supported by Java bc it ___ the complexity of programming

final

if a class is tagged as ____, then it cannot be extended

String

the ____ class in Java is final

overrriden

if a method is tagged as final, then it cannot be _____

attribute

if an ____ is tagged as final, then it cannot be changed

constructors

______ cannot be tagged as final

inheritance, aggregation

_____ decreases readability, avoid overusing it (use ___ instead)