Author Archives: Mr. M

Chapter 9

Great picture of synchronous vs asyncronous

Retrieved from https://msdn.microsoft.com/en-us/library/ms917361.aspx

Problem Solving Process

The problem Solving Process (ch 7.1)

Taken From JB Learning’s super awesome book/powerpoint set “Computer Science Illuminated

http://www.jblearning.com/catalog/9781449672843/

Compiled and Interpreted Languages

Comilers and Interpreters

Retrieved from http://en.wikibooks.org/wiki/Introduction_to_Programming_Languages/Interpreted_Programs

retrieved from http://www.greenteapress.com/thinkapjava/html/thinkjava003.html

retrieved from http://www.pasteur.fr/formation/infobio/python/ch05s02.html

Alice- What as a String

You cannot place a number variable into the say() method

You must use the World function : what as a string

NEXT: asking user for input and saying it

Class Roster Array Version [Java] Assignment

Class Roster: This class will implement the functionality of all roster for school. It will , in essence, manage an Array of Student objects. Each roster will store a default of 10 Students

“global” Instance Variables
- private Student myStudents : an array storing Student Objects
- private String className (a name to represent a given roster like “Ap CS”)
- public int period //during which period of the day does this roster meet
a default constructor should initialize the Array to store 20 strings
a single parameter constructor that takes an Array <String>
Both constructors should initialize the instance variables
Methods
- Accessors
  - private int indexOf(Student st) //@returns index of Student St or -1
  - public boolean containsStudent(Student studentName )/ /@returns true if studentName is in roster .
  - public boolean equals(ClassRoster other) //@ returns whether or not rosters are equal. Rosters are equal if identical students are in identical order in the lists
- Mutators:

boolean addStudent( Student st ) ;//adds the student to the Roster

1	boolean addStudent( Student st ) ;//adds the student to the Roster

public void addStudent(String studentName, int age) ;// adds student name and age to end of roster

. Hint: Make user of the containsStudent() method
public boolean removeStudent(int ssnId ) // removes student from roster based on id. Make sure that you maintain the integrity of the parallel ArrayLists.

public boolean removeStudent(String name) //removes student based on name. Make sure that you maintain the integrity of the parallel ArrayLists.

public boolean removeStudent( Student st) //removes student st. Make sure that you maintain the integrity of the parallel ArrayLists.

Student Runner Part 2

public class StudentsRunner2{

public static void main(String[] args){
//insert the line of code needed to create the Student object aStudent;
String teacher;
for (int i =0 ;i <  5; i++)
  {
   teacher= inputString("Enter a teacher");
   aStudent.addTeacher(teacher);
  }
}


}

public class StudentsRunner2{

public static void main(String[] args){

//insert the line of code needed to create the Student object aStudent;

String teacher;

for (int i =0 ;i < 5; i++)

{

teacher= inputString("Enter a teacher");

aStudent.addTeacher(teacher);

}

1) Construct the Java statement to create the Student object called aStudent in the

StudentsRunner

Back to the Student Class

Students Runner Class

public class StudentsRunner{

public static void main(String[] args){

Student dom;

}


}

public class StudentsRunner{

public static void main(String[] args){

Student dom;

}

1) Construct the Java statement to create the Student object called Dom in the

StudentsRunner

Next to Student Runner Part 2

Back to the Student Class

Student Object (OOP Java)

Student Class

A school district decided to write a program to help keep track of various parts of the school.

It has been decided to store relevant information about Students in a Student class. Each Student will have an array of Strings to store the names of his or her teachers.

private instance variables

public class Student
{
public String name;
private int age
private double gpa;
private //insert array declaration;

public Student(){} // default constructor

boolean setTeacher (String name, int index){
//missing code
}

public void setGpa(double to){
//missing code
}

public double getGPA() // returns gpa


}

public class Student

{

public String name;

private int age

private double gpa;

private //insert array declaration;

public Student(){} // default constructor

boolean setTeacher (String name, int index){

//missing code

}

public void setGpa(double to){

//missing code

}

public double getGPA() // returns gpa

}

Part 1

* Construct the Java statement to declare the array called

teachersNames to store the String names of the student’s teachers

Part 2

write a default constructor
construct a method called addTeacher( String name) that adds String name to the teachersNames array
- to do this let’s create a private method private String[] addStr( String[] input, String val) that adds value to the end of the array and returns it. [redact]Solution[/redact]
construct hasTeacher(String name) that returns true if name is in the teachersName array
construct a method removeTeacher(String name) that removes the String name from the teachersNames array.
construct a method the line of code needed in the setGpa(double to) method of the Student Class.
construct a method boolean setTeacher (String name, int index) . This method should return true if index is valid in the array and false if index >= teachersName.length

Next: The runner class

Playlist Project [Array]

A PlayList project will be based on Three Classes

Artist
Song
PlayList

The Artist class will store core information about an artist

The Song class will store basic information about a music song

The PlayList class will manage lists of songs and artists

Artist

Constructor(s) :
public Artist( String name) { //missing code }

Instance Variables (“global” variables)

private String artistName ;
private Song[]  songs ; - an array storing the songs of this artist

1 2	private String artistName ; private Song[] songs ; - an array storing the songs of this artist

Methods

private int indexOf(String songName) // returns index position of parameter in the array 
public void addSong(Song song) 
public void removeSong(Song song) public void removeSongByName(String songName) 
public Song[] getSongs() //returns songs array
public String getName() // returns artistName

private int indexOf(String songName) // returns index position of parameter in the array

public void addSong(Song song)

public void removeSong(Song song) public void removeSongByName(String songName)

public Song[] getSongs() //returns songs array

public String getName() // returns artistName

Song

Constructor(s):

public Song(String songName, Artist artist){
//missing code 
}

public Song(String songName, Artist artist){

//missing code

}

Instance Variables

private Artist artist ;
public String songName ;
public long date //(date added to list)

private Artist artist ;

public String songName ;

public long date //(date added to list)

example of how to get current milliseconds as a long

Method

public Artist getArtist()

1	public Artist getArtist()

Artist

Song

PlayList

Instance Variables
- private String listName : This is the ‘name’ of your playList
- private Song[] songs;
- private int[] stars ; //how many stars each song has between 0 and 5 inclusive.
- Note: songs and stars are parallel Arrays
Constructor
- public PlayList(String name) : There should be only 1 constructor that takes a parameter representing the name of the playList
Accessor Methods
- public double averageRating() // returns the average star rating for the list
- public double averageRating(Artist artist) // returns the mean star rating associated with artist
- public Song[] getSongs(Artist artist) // returns an array populated by the songs of the parameter artist
- public Song[] getSongs() // returns all the songs in the list
Mutator Methods
- public void swap(Song song1 , Song song2 ) // switches positions of these two (maintain parallelism!)
- public void add(Song song , int stars)
- public void removeSong(Song song, String artist ) //removes song associated with artist
  - Note: Be careful here. You are allowed to add the same song and artist. Duplicates are allowed.
- public void removeArtist(Artist artist ) //removes all elements associated with artist
- public void removeLowStars(int cutOff) //removes all elements associated with a star rating less than cutOff
- ** public PlayList sortByDate() //this returns a rearranged PlayList based on each Song’s date
- ** public PlayList sortByRating() //this returns a rearranged playlist so that the 5 starred elements are the first group in the list, 4 stars second …1 stars, last
- ** public PlayList shuffle() //this returns a new PlayList in which all of the songs have been reordered randomly.