Java fundamentals: extra labs

Lesson 6

Extra practice: Extend Customer Info

1. Modify lab 6.1 to ask the user to enter the attributes of the customer
2. Use java.util.Scanner to read the attributes
1. Take care: after reading an int, you also need to read the return (newline) to advance to the next line of input

Lesson 7

Practice 7.1:

Modify the exercise to:

1.     Use a java.util.Scanner to read the time of the day from the user input.
2.     Allow the user to use the format hh:mm:

Extra practice: Seasons

1.  Create a class Meteo with a method
    public String getSeason(String month) 

2.  Implement the method and let it return the meteorological season for the month 
1. (e.g. for december to february return winter)
3. Create a class MeteoTest
4. Write a main method that
1. Creates a Meteo object
2. Asks the user for the name of a month
3. Uses the Meteo object to get the corresponding season
4. Prints out the season
5. Run the test program and correct errors until it succeeds
6. Modify the program to make it work no matter which case the user uses when entering the month.
7. Run the test program and correct errors until it succeeds

Lesson 8

Extra practice: Deck

1. Create a class Deck  
2. Initialise a cardNames array with the value of all cards (ace, two, three..., jack, queen, king)
3. Initilise a cardSuites array with the suites of all cards (hearts, spades, clubs, diamonds)
4. Create a method called printSize, which
1. prints the number of cardValues
2. prints the number of cardSuites
3. prints the number of cards
5.  Create a class DeckTest
6. Write a main method that
1. Creates a Deck object
2. Calls printSize on it
3. Run the test program and correct errors until it succeeds
7. Write a method drawCard, which prints the name of a random card (e.g. jack of spades)
1. Hint: use Math.random()
8. Draw two cards from the main method
9. Run the test program and correct errors until it succeeds

Lesson 9

Extra practice: Dice

1.  Create a class DiceStat with a method
    public void printStat () 

2. The method should roll 2 dice 10.000 times (Hint: use Math.random()
3. Print the number of times each number was rolled
4.  Create a class DiceTest
5. Write a main method that
1. Creates a DiceStat object
2. Calls printStat
6. Run the test program and correct errors until it succeeds
7. For each result, express as a percentage, how often it is thrown
8.  Run the test program and correct errors until it succeeds

Extra practice: Factorials

A factorial (n!) is the product of all numbers less than or equal to n. Example:

3!= 3*2*1

Create an application, called factor that will print the factorial of the number given as an argument to the application:

$ java FactorTest 3
3! = 6

Lesson10

Extra practice: Quiz

1.  Create a class Quiz with keywords and definitions.You can find the keywords and definitions here.
2. Create a method with signature
    public boolean askQuestion()
1. The method asks the user to give the keyword that corresponds to a randomly chosen definition
2. The method compares the answer with the  keyword
3. The method informs the user about the correctness of the result.
4. If the answer was wrong, it shows the correct keyword
5. The method returns if the respons is correct
3. Create a class QuizTest
4. Write a main method that
1. Creates a Quiz object
2. Calls askQuestion
5. Run the test program and correct errors until it succeeds
6. Add a method with this signature
      public int askQuestions(int number) 
1. The method asks multiple questions
2. The method returns the number of correct answers
7. Call the method from the main class
8. Run the test program and correct errors until it succeeds
9. Add a method with this signature
 public boolean certify (int numberOfQuestions, int passPercentage)
1. The method prints out your score percentage.
2. The method prints out whether you passed the certification or not.
3. The method returns a boolean with the pass result.
10. Call the certify method from the main class
11. Run the test program and correct errors until it succeeds

Extra practice: Hypothenuse

The hypotenuse is the longest side in a right angled triangle. Pythagore's theorem states that the length of the hyothenuse (h) relates to the two other sides (x and y)  as:

Write a program, using that calculates the hypothenus, using java's Math class:

$ java HypothenuseTest 2 3
Hypothenuse = 3.6

Lesson 11

Extra practice: Unique object ID's

1.  Modify the Rectangle class to assign a unique ID to each object that is created.
1. Start the ID's at 1 and increment for each new object
2. Print the rectangle ID in the creation message from the constructor
2.  Run the test program and correct errors until it succeeds

Extra practice: Deck

1.  Add a Card class to the Deck project
1. Add a suit and value attribute and methods to retrieve them
2. Add a Constructor 
3. Add a method that returns the card name (e.g. queen of hearts) with signature
     public String toString(); 
2. Add a constructor to the Deck class that generates a Deck of 52 cards.
3. Modify the drawCard method to return a Card
4. After calling drawCard, print out the card name from the main method.

Extra practice: Dice constructor

1. Add a constructor to the DiceStat class that accepts the number of dies, the number of sides each dice has and the number of throws.
2. Make the Deck class generic to work with these variables.
3. Run the test program and correct errors until it succeeds

Lesson 12

Extra practice: Rectangle class hierarchy

1. Make a class Square, that is a subclass of the Rectangle class. 
1. Add a Constructor that takes the side as an aargument
2. Draw a square from the RetcangleTest main method
3. Run the test program and correct errors until it succeeds
4. Make rectangle a subclass of Shape. Make a class Shape with an abstract draw method.
1. In Rectangle you can also use Refactor => extract interface
5. Make a Triangle class that extends Shape (In the interface, you can press ALT+ENTER to generate a class that implements the interface)
1. This class is a right angled triangle, with equal width and height. Example:
*
**
***
****
2. Implement the necessary methods
6. Draw a triangle from the RetcangleTest main method
7. Run the test program and correct errors until it succeeds
8.  Make a Canvas class, with a method with signature
public void draw (List shapes)

1. In the draw method  loop over the list
2. Assign the objects from the list to a Shape variable
3. Draw each Shape
9. In the main method of TestRectangle, create a Canvas
10. Add a number of rectangles, Squares and triangles to an Arraylist.
11. Call the draw method on the canvas, and pass the arraylist to it.
12. Run the test program and correct errors until it succeeds
13. Make a Parallellogram class that extends Shape (you can make a copy of the Rectangle class and name it Parallellogram to start)
1. This class draws a parallellogram with a slope that indents one character:
****
 ****
  ****
2.  Implement the necessary methods
14. In the main method of TestRectangle, add some paralellograms to the ArrayList
15. Run the test program and correct errors until it succeeds

Firefox on windows 64 bit : use the 32 bit plugins

When installing the java plugin on windows 64 bit (I have windows 7), which Java plugin do I need?
64 bit seems the logical choice.
Here's what Oracle, steward of Java says at this time:

Java for 64-bit browsers

Users should download 64-bit Java software, if they are running 64-bit browsers.

Allright, now do I have a 64 bit firefox, the page tells me how to check

Verify if you are using 32-bit or 64-bit browser

Firefox

To determine whether you are running on a 64-bit version of Firefox, use either of these methods.

• Check the About Firefox panel
• Type in the browser address about:support

If you are running 64-bit Firefox, it may be indicated as 64-bit (e.g., Win64); otherwise it is a 32-bit version of Firefox.  

 What can I find on this page?

 User Agent     Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Firefox/24.0

There's a number 64 in there, but take care: this indicates that windows is 64 bit. To really know more about your firefox you need to follow the about:buildconfig link. oracle should recommend to type that one directly. Look at the target entry:

target i686-pc-mingw32

This is a 32 bit build after all. As a matter of fact, Firefox does currrently not provides a production quality 64 bit build for Windows. On Windows, Firefox currently is a 32 bit application, hence you always take the 32 bit plugins.

Excel 2010 Advanced Filtering

The official excel (advanced) filtering doc is a step by step guide for some common cases, but does not explain well how it actually works.
The common case is not what i commonly need, so I lose time and patience looking this up.
So I'd better keep a good excel advanced filtering resource around in case I ever need this again.

Remark: every time you change your filter (or sorting) criteria, you have to point the advanced filter to the filtering criteria again. The only way to avoid this is to add a macro to your spreadsheet.

Adidias NEO window dressing

My colleague Eytan pointed me to this Video on Adidas window shopping.
Adidas mounted a giant touch screen in front of the shopping window,
on which you can by goods using a tablet interface.
Looks great!