3.13
public class Account
{
private double balance;
public Account(double initialBalance){
if(initialBalance > 0.0)
balance = initialBalance;
}
public void credit(double amount){
balance = balance + amount;
}
public double getBalance(){
return balance;
}
}
3.14
import java.util.Scanner;
public class AccountTest
{
public static void main(String[] args){
Account account1 = new Account(50.00);
Account account2 = new Account(-7.53);
System.out.printf("account1 balance: $%.2f\n", account1.getBalance());
System.out.printf("account2 balance: $%.2f\n", account2.getBalance());
Scanner input = new Scanner(System.in);
double depositAmount;
System.out.print("Enter deposit amount for account1: ");
depositAmount = input.nextDouble();
System.out.printf("\nadding %.2f to account1 balance\n\n", depositAmount);
account1.credit(depositAmount);
System.out.printf("account1 balance: $%.2f\n", account1.getBalance());
System.out.printf("account2 balance: $%.2f\n", account2.getBalance());
System.out.print("Enter deposit amount for account2: ");
depositAmount = input.nextDouble();
System.out.printf("\nadding %.2f to account2 balance\n\n", depositAmount);
account2.credit(depositAmount);
System.out.printf("account1 balance: $%.2f\n", account1.getBalance());
System.out.printf("account2 balance: $%.2f\n", account2.getBalance());
}
}
import javax.swing.JOptionPane;
public class Dialog1
{
public static void main (String[] args)
{
JOptionPane.showMessageDialog(null,"Welcome to java");
}
}
import javax.swing.JOptionPane;
public class NameDialog
{
public static void main(String[] args)
{
String name=JOptionPane.showInputDialog("What is your name?");
String message=String.format("Welcome, %s, to Java Programming!", name);
JOptionPane.showMessageDialog(null, message);
}
}
import javax.swing.JOptionPane;
public class AccountTestDialogBox
{
public static void main (String[] args)
{
Account account1 = new Account (50.00);
Account account2 = new Account (-7.53);
String output1 = String.format ("account1 balance : $%.2f\naccount2 balance : $%.2f\n\n", account1.getBalance(), account2.getBalance());
JOptionPane.showMessageDialog (null, output1);
String input1 = JOptionPane.showInputDialog ("Enter deposit amount for account1 : ");
Double input1a = Double.parseDouble (input1);
account1.credit (input1a);
String message1 = String.format ("\nadding %s to account1 balance\n\n", input1);
JOptionPane.showMessageDialog (null, message1);
String output2 = String.format ("account1 balance : $%.2f\naccount2 balance : $%.2f\n\n", account1.getBalance(), account2.getBalance());
JOptionPane.showMessageDialog (null, output2);
String input2 = JOptionPane.showInputDialog ("Enter deposit amount for account2 : ");
Double input2a = Double.parseDouble (input2);
account2.credit (input2a);
String message2 = String.format ("\nadding %s to account2 balance\n\n", input2);
JOptionPane.showMessageDialog (null, message2);
String output3 = String.format ("account1 balance : $%.2f\naccount2 balance : $%.2f\n", account1.getBalance(), account2.getBalance());
JOptionPane.showMessageDialog (null, output3);
}
}
