Mid+Term+Review+2015

7/21/2019 Mid+Term+Review+2015

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Mid Term Review 2015 Winter

Exam Format

true/false and/or multiple choice questions

short-answer questions, e.g.

o define something, explain something, list things

o fill in the blank, answer a question about a diagram/screen shot

o write one or two statements to perform a certain task

o write short coding statement

1 coding problem (written, or using computer)

Topics Covered

String Processing

strings are immutable - what does this mean? how characters are stored in a string obect

how string obects are created ? how string obect are stored in memor!

how concatenation affects a string obect ? string comparison" ## $s. equals()

%tring class methods & 'haracter class methods

'on$ersion methods used to con$ert $arious t!pes of data to %tring obects

'omparing strings with .equals(), checking for null-string ()

OOP Review

* - creating classes, accessor/mutator methods, constructor methods, the this

ke!word, to%tring() and equals() methods, etc.

+ class diagram, 'reating class in + format

'reating static methods $s. non-static methods. h! client class methods are not static?


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%tatic methods and static $ariable, finall!, wh! do we need them?

n!eritance

hat is inheritance, how does it work? h! use inheritance?

erms" *arent class/child class& super class/sub class& base/deri$ed class

how to code a child class - extends ke!word

he super ke!word - e.g. super.something or super()

child class inherits stuff from parent class& !ou can change (o$erride) methods or add

methods/$ariables

d!namic binding - what does this mean, how does it work, effects, etc.

%imple/%ingle-inheritance $s. multiple-inheritance - which does 0a$a support?

ethod o$erriding

casting parent/child classes (assigning reference of the parent class obect of a child class)

Misc" OOP Concepts

'lass design - t!pes of class relationships" composition, aggregation, inheritance&

characteristics of good program or class design, etc. (see *ower*oint from this lesson)

+ class relationship diagram, classes relationship in + format

bect class - top of the hierarch!. hat is inside bect class?

to%tring(), equals() - inherited from obect

implicit call to to%tring() method e.g. %!stem.out.println(obectariable)&

2ow obects and obect/reference $ariables are stored in memor!, comparing obects with

## $s. .equals()

instanceof operator

*ol!morphism - what does this mean? 3!namic binding ?


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ethod o$erloading $s. method o$erriding - what4s the difference? 5xamples6

#$stract C%asses&Met!ods&nter'aces

2ow do !ou define a class/method as abstract?

hat are abstract classes/methods& wh! do we need them?

7bstract methods

o methods with ust a signature, no bod!

o often used in parent classes to include empt! methods that onl! child classes will

implement

7bstract classes

o a class with at least one abstract method

o can contain attributes and methods that are implemented (ha$e code)

8nterfaces

o h! do we need them? 2ow do define?

o 2ow to use?

o 8nterface usage in 9+8 model

ntro to ()

a. 9+8 'omponents

b. a!out anagement. +sing a!outsc. 8ntro to 5$ent 2andling

d. 5$ent 2andling *ractices

Primitive *ata O$+ects

rapper classes - what the! are, names, what the!4re for, etc.

he hierarch! of the wrapper classes - child/parent, :umber class, etc.

+seful methods and constants e.g. 7;


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rapper 'lasses ? =or example, >oolean class -- parse>oolean() and booleanalue()

methods and how the! work

Misc"

a$adoc - con$entions, tags, what the!4re for, etc.

packages - what are the!, wh! use them, how to create, naming con$entions

Samp%e ,-estions

Coding

1" #n. o' programs 'rom /ome #ssignments& Practic-m & a$ co-%d $e considered as

an examp%e"

. 5xample " 7 class called *erson is defined as follows"

public class Person

{

private String firstName;

private String lastName;

private String phone;

private String address;

public Person() {}

public Person(String firstName, String lastName, String address,

String phone) {

setFirstName(firstName);

setLastName(lastName);

setddress(address);

setPhone(phone);

}

public void setFirstName(String name) thro!s "llegalrgument#$ception

{

if (name%e&uals(''))

thro! ne! "llegalrgument#$ception('"nvalid first

name%');

else

firstName name;

}

public String getFirstName() { return firstName; }

public void setLastName(String name) thro!s "llegalrgument#$ception

{

if (name%e&uals(''))


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thro! ne! "llegalrgument#$ception('"nvalid last

name%');

else

lastName name;

}

public String getLastName() { return lastName; }

public void setddress(String address) thro!s "llegalrgument#$ception

{

if (address%e&uals(''))

thro! ne! "llegalrgument#$ception('"nvalid address%');

else

this%address address;

}

public String getddress() { return address; }

public void setPhone(String phone) thro!s "llegalrgument#$ception

{

if (phone%e&uals(''))

thro! ne! "llegalrgument#$ception('"nvalid phone

number%');else

this%phone phone;

}

public String getPhone() { return phone; }

public String toString() {

return 'Name ' * lastName * ', ' * firstName * '+nPhone '

* phone * '+nddress ' * address;

}

}

3efine a class called %tudent as a child class of *erson with the following specifications"

%tring attributes for first name, last name, address, and phone number. hese must not be

empt!, or an exception is thrown.

7 %tring attribute for student id, which is alwa!s exactl! @ digits. :o letters are allowed.

8f an id is in$alid, an 5xception with the message 8n$alid student 83. is thrown.

7 %tring attribute for program code, which is alwa!s exactl! four characters. hese

characters could be letters, digits, or an! combination of letters and digits. 8f the program

code is in$alid, throw an 5xception with the message 8n$alid program code.

7 default constructor that contains no code. his allows the programmer to create an

empt! obect and set the $alues later.

7 six-parameter constructor that takes the id, first name, last name, address, phone

number, and program code, and sets the $alues of those $ariables.


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7ccessor/mutator methods for the attributes.

7n equals() method that checks to see if two student obects are equal. wo %tudents are

equal if the! ha$e the same student 83.

a to%tring() method that returns a string representation of a student in the following form(sample $alues used for the data)"

" -./012345

Name Schmoe, 6oe

Phone 5718401850/7

ddress -77 9ain St%

Program /..7

}

Documents

Mid+Term+Review+2015