Transcript Using break and continue

Using break and continue
Examples 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,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);
}
}
• // TestContinue.java: Test the continue keyword,13
• public class TestContinue {
• /** Main method */
• public static void main(String[] args) {
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int sum = 0;
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int item = 0;
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while (item < 5) {
item++;
if (item == 2) continue;
sum += item;
}
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System.out.println("The sum is " + sum);
• }
• }
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–$5,000
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
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final double COMMISSION_SOUGHT = 25000;
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final double INITIAL_SALES_AMOUNT = 0;
•
double commission = 0;
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double salesAmount = INITIAL_SALES_AMOUNT;
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do {
// Increase salesAmount by 1 cent
salesAmount += 0.01;
• // Compute the commission from the current salesAmount;
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if (salesAmount >= 10000.01)
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commission =
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5000 * 0.08 + 5000 * 0.1 + (salesAmount - 10000) * 0.12;
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else if (salesAmount >= 5000.01)
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commission = 5000 * 0.08 + (salesAmount - 5000) * 0.10;
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else
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commission = salesAmount * 0.08;
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} while (commission < COMMISSION_SOUGHT);
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// Display the sales amount
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String output =
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"The sales amount $" + (int)(salesAmount * 100) / 100.0 +
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"\nis needed to make a commission of $" +
COMMISSION_SOUGHT;
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JOptionPane.showMessageDialog(null, output,
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"Example 3.7 Output",
JOptionPane.INFORMATION_MESSAGE);
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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
4321234
543212345
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 */
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public static void main(String[] args) {
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final int NUM_OF_LINES = 5;
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for (int row = 1; row <= NUM_OF_LINES; row++) {
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// Print leading spaces
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for (int column = 1; column <= NUM_OF_LINES - row; column++)
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System.out.print(" ");
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// Print leading numbers
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for (int num = row; num >= 1; num--)
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System.out.print(num);
• // Print ending numbers
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for (int num = 2; num <= row; num++)
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System.out.print(num);
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// Start a new line
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System.out.println();
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}
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}
• }
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.