Week 5 Lecture 2 Class Exercises

Exercise 1: Packages

1. Individually write an explanation for the purpose of a Java package.
2. When you and your partner have both completed your answers, compare them and determine which answer you like better (and why).
3. Write a new an improved answer together.

Exercise 2: Coding Conventions

1. Individually write an explanation for the purpose of a coding convention.
2. When you and your partner have both completed your answers, compare them and determine which answer you like better (and why).
3. Write a new an improved answer together.
4. List the main areas that the Oracle coding conventions document addresses.
5. List important coding conventions that you need to be aware of as you continue writing code this year.

Exercise 3: Random Numbers

Using documentation for the java.util.Random class write code to generate random numbers with the following characteristics:

• An integer value between 0 and 15 (including 0, but no including 15)
• An integer value between 5 and 10
• A double value between 0.0 and 1.0
• A double value between 0.0 and 100.0
• A double value between -100.0 and 100.0

Exercise 4 (optional): System.out.printf

Using documentation for the java.io.PrintStream.printf method and the format string syntax make use of System.out.printf to:

1. Display "There are 8 chocolate bars each of the 5 bags" where the numbers are stored in integers, numBars and numBags.
2. Display "The COW JUMPED over the MOON" where the all caps words are stored in strings: noun1, verb, and noun2.
3. Display "The 8 COWs JUMPED over the MOON" where the 8 is stored in an integer, number, and the all caps words are stored in strings: noun1, verb, and noun2.
4. Display PI with 5 significant digits.
5. Display five integers (each on a separate line) so that they are right justified, e.g.,

        13
      1872
   8238820
         3
       -73
   

6. Display a table with a heading and three additional rows with the following format (assume all values come from variables):

   Name       Address
   ====       =======
   John       123 8th St.
   Wendy      231 3rd Ave.
   Edwardo    321 Lethanderson Way
   

7. Display five doubles (each on a separate line) so that they are right justified and have 3 places to the right of the decimal, e.g.,

     100.135
      -3.700
   70003.888
      23.456
       3.142