Introduction to Object Oriented Systems Development. Practical Session (Week 2)

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1 This practical session consists of three parts. Practical Session (Week 2) Part 1 (Tutorial). Starting with NetBeans In this module, we will use NetBeans IDE (Integrated Development Environment) for Java programming. In this tutorial you will write, compile and run your first Java program (consisting of one class and the main method only) using the NetBeans IDE. Another goal of this tutorial is to learn how to use NetBeans. You will be guided through the following steps: 1. Creating a folder to store ALL your NetBeans work on this module. 2. Starting NetBeans and creating a project 3. Create a package 4. Creating a Java main program 5. Edit the program 6. Compile and run the program Note that you will be doing Steps 1 & 2 once only on this module. The screenshots shown were taken from my laptop, which may slightly differ from your desktop/laptop. Step 1. Creating a folder to store ALL your NetBeans work Simply make a folder called mynetbeans on a convenient drive. It is recommended that you use a USB drive so you can work on your project anywhere. In this example we use a USB drive mounted as the R: drive. Step 2. Start NetBeans and create a project Click on Netbeans in the Windows Start menu. Then click on File followed by New Project to create a new project: Page 1 of 9

2 Click on Next. Now, fill in Project Name with OOSD1 and browse Project Location to R:\mynetbeans folder. Untick the Create main class box. Click on Finish. Page 2 of 9

3 You will not need to create another project for this module. Step 3. Create a package Right click on the Source Packages node and create a Java Package called general Note: If you ever cannot see an option on this drop down list then choose "Other..." Page 3 of 9

4 Step 4. Create a Java main program Right click on the general package node, then New -> Java Main Class to create a new Java Main Class called Hello (if the Java main class is not on the drop down menu, first choose Other and then Java -> Java Main Class). On the next screen fill in Class Name with Hello. Page 4 of 9

5 Click on Finish. You should get a program that looks like this: package general; /** my-name */ public class Hello { public static void main(string[] args) { // TODO code application logic here } //main } //class Step 5. Edit the program Replace the line: // TODO code application logic here with System.out.println("Hello Big World!!!"); Step 6. Compile and run the program Right click on the program Hello.java node and choose Run File (this will compile automatically and save). Page 5 of 9

6 After running the program you should get the output shown below. Congratulations......you have written, compiled and run your first Java program (class) using the NetBeans IDE. Note: You will typically need to repeat Steps 3, 4, 5 and 6 for your practical exercises, class tests and assignment, that is, to create a package, design and write a program, and edit, compile and run the program. Please make sure that you fully understand what is involved in each of these steps. Part 2. Variables, primitive data types, assignments, expressions, operators, named Page 6 of 9

7 constants, and input and output In this exercise, you are required: first, to create a Java Package called practical2part2 in the project called OOSD1 that you have already created; second, to design and write a Java program for calculating the Total Money we spent last month. The program uses three variables as input for Food, Leisure and Clothes expenses, and it uses another variable as output for the total money spent as output. Step 1. Right click on the practical2part2 package node and create a new Java Main Class called MonthlyExpenditure. Step 2. Add the description of the program as a comment. Step 3. Edit and run the program (a). Replace the line: // TODO code application logic here with the following code: double foodexpenses = 300.0; double leisureexpenses = 100.0; double clothesexpenses = 50.0; double totalspent; totalspent = foodexpenses + leisureexpenses + clothesexpenses; System.out.println("The total expenditure this month was " + totalspent); (b) Edit the given sample program to calculate your total money spent last month on food, leisure and clothes. Run the edited program. (c) Extend the given sample program so that it can be used to calculate your total money spent last month food, leisure, clothes, accommodation and travel. Run the extended program. (d) Further extend the given sample program so that it can used to take input from the keyboard, calculate your total money spent last month food, leisure, clothes, accommodation and travel, and display your total money on the screen. Run the further extended program. (e) Assume that you spend a fixed amount on your accommodation expenses each month. Change your extended sample program in which your accommodation expenses are represented as a named constant. Run your final program. In this part, you have done your very first case study programming exercise. Please make sure you have fully understood what has been covered in this case study programming exercise, including how to create a Java Package and the Java Main Class, and all those relevant programming concepts. This case study will have provided a good mock-up practice for your first class test scheduled for your practical session in Week 3. The format and structure of your first class test will be similar to this exercise. Page 7 of 9

8 Part 3. More Programming exercises Use the remainder of this practical session to do the following exercises in Liang s textbook. You may not be able to complete all the exercises in this practical session but you should complete any remaining exercises at your own time. These are just a few programming exercises at the end of Chapter 2 in Liang s textbook. You are encouraged to select and do as many exercises as you can. Note: You should name and create a Java Package for Part 3, called practical2part3, and then create a Java Main Class for each of the exercises. *1.11 (Population projection) The U.S. Census Bureau projects population based on the following assumptions: One birth every 7 seconds One death every 13 seconds One new immigrant every 45 seconds Write a program to display the population for each of the next five years. Assume the current population is 312,032,486 and one year has 365 days. Hint: In Java, if two integers perform division, the result is an integer. The fractional part is truncated. For example, 5 / 4 is 1 (not 1.25) and 10 / 4 is 2 (not 2.5). To get an accurate result with the fractional part, one of the values involved in the division must be a number with a decimal point. For example, 5.0 / 4 is 1.25 and 10 / 4.0 is (Convert Celsius to Fahrenheit) Write a program that reads a Celsius degree in a double value from the console, then converts it to Fahrenheit and displays the result. The formula for the conversion is as follows: fahrenheit = (9 / 5) * celsius Hint: In Java, 9 / 5 is 1, but 9.0 / 5 is 1.8. Here is a sample run: **2.13 (Financial application: compound value) Note: This is a challenging exercise. You are encouraged to form a group of two or three students to do the exercise as a team. Suppose you save $100 each month into a savings account with the annual interest rate 5%. Thus, the monthly interest rate is 0.05/12 = After the first month, the value in the account becomes 100 * ( ) = After the second month, the value in the account becomes ( ) * ( ) = After the third month, the value in the account becomes ( ) * ( ) = and so on. Page 8 of 9

9 Write a program that prompts the user to enter a monthly saving amount and displays the account value after the sixth month. (You will use a loop to simplify the code and display the account value for any month in your practical session in Week 4.) Page 9 of 9