Using break and continueExamples for using the break and continue keywords:

Example 3.5: TestBreak.java

Example 3.6: TestContinue.java

// TestBreak.java: Test the break keyword in the loop,15public 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); }}

• // 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);• }• }

3.7 Finding the Sales AmountYou 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–$5,000 8 percent$5,000.01–$10,000 10 percent$10,000.01 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.

• // 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;• •

• // Compute the commission from the current salesAmount;• if (salesAmount >= 10000.01)• commission = • 5000 * 0.08 + 5000 * 0.1 + (salesAmount - 10000) * 0.12;• else if (salesAmount >= 5000.01)• commission = 5000 * 0.08 + (salesAmount - 5000) * 0.10;• else• commission = salesAmount * 0.08;• } while (commission < COMMISSION_SOUGHT);• // Display the sales amount• String output = • "The sales amount $" + (int)(salesAmount * 100) / 100.0 + • "\nis needed to make a commission of $" + COMMISSION_

SOUGHT;• JOptionPane.showMessageDialog(null, output, • "Example 3.7 Output", JOptionPane.INFORMATION_MESS

AGE);• System.exit(0); • }

3.8 Displaying a Pyramid of Numbers

In this example, you will use nested loops to print the following output:

1 212 32123 4321234543212345

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 3 2 1 on line 3; and the last part, the ending numbers, such as 2 3 on line 3.

• // 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++)• System.out.print(num);• // Start a new line• System.out.println();• }• }• }

3.9 Displaying Prime NumbersThis 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.