1. Using break and continue
Examples for using the break and continue keywords:
Example 3.5: TestBreak.java
Example 3.6: TestContinue.java

2. // TestBreak.java: Test the break keyword in the loop,15 public class TestBreak { /** Main method */ public static void main(String[] args) { int sum = 0; int item = 0; while (item < 5) { item ++; sum += item; //if (sum >= 6) break; } System.out.println("The sum is " + sum); } }

3. // TestContinue.java: Test the continue keyword,13
public class TestContinue {
/** Main method */
public static void main(String[] args) {
int sum = 0;
int item = 0;
while (item < 5) {
item++;
if (item == 2) continue;
sum += item; }
System.out.println("The sum is " + sum);

4. 3.7 Finding the Sales Amount
You have just started a sales job in a department store. Your pay consists of a base salary and a commission. The base salary is $5,000. The scheme shown below is used to determine the commission rate.
Sales Amount Commission Rate
$0.01–$5, percent
$5,000.01–$10, percent
$10, and above 12 percent
Your goal is to earn $30,000 in a year. Write a program that will find out the minimum amount of sales you have to generate in order to make $30,000.

5. // FindSalesAmount.java: Find the sales amount to get the
// desired commission.Base salary 5000,earn30000 a yr.
import javax.swing.JOptionPane;
public class FindSalesAmount {
/** Main method */
public static void main(String[] args) {
// The commission sought
final double COMMISSION_SOUGHT = 25000;
final double INITIAL_SALES_AMOUNT = 0;
double commission = 0;
double salesAmount = INITIAL_SALES_AMOUNT;
do {
// Increase salesAmount by 1 cent
salesAmount += 0.01;

6. // Compute the commission from the current salesAmount;
if (salesAmount >= )
commission =
5000 * * (salesAmount ) * 0.12;
else if (salesAmount >= )
commission = 5000 * (salesAmount ) * 0.10;
else
commission = salesAmount * 0.08;
} while (commission < COMMISSION_SOUGHT);
// Display the sales amount
String output =
"The sales amount $" + (int)(salesAmount * 100) /
"\nis needed to make a commission of $" + COMMISSION_SOUGHT;
JOptionPane.showMessageDialog(null, output,
"Example 3.7 Output", JOptionPane.INFORMATION_MESSAGE);
System.exit(0); }

7. 3.8 Displaying a Pyramid of Numbers
In this example, you will use nested loops to print the following output: 1
212
32123
Your program prints five lines. Each line consists of three parts. The first part comprises the spaces before the numbers; the second part, the leading numbers, such as on line 3; and the last part, the ending numbers, such as 2 3 on line 3.

8. // PrintPyramid.java: Print a pyramid of numbers
public class PrintPyramid {
/** Main method */
public static void main(String[] args) {
final int NUM_OF_LINES = 5;
for (int row = 1; row <= NUM_OF_LINES; row++) {
// Print leading spaces
for (int column = 1; column <= NUM_OF_LINES - row; column++)
System.out.print(" ");
// Print leading numbers
for (int num = row; num >= 1; num--)
System.out.print(num);
// Print ending numbers
for (int num = 2; num <= row; num++)
// Start a new line
System.out.println(); }

9. 3.9 Displaying Prime Numbers
This example displays the first 50 prime numbers in five lines, each of which contains 10 numbers. An integer greater than 1 is prime if its only positive divisor is 1 or itself. For example, 2, 3, 5, and 7 are prime numbers, but 4, 6, 8, and 9 are not.
The problem can be broken into the following tasks:
For number = 2, 3, 4, 5, 6, ..., test whether the number is prime.
Determine whether a given number is prime.
Count the prime numbers.
Print each prime number, and print 10 numbers per line.