JavaSection562

// Guide to Java
// Copyright 2014, by J.T. Streib and T. Soma

// a program to create card, make purchases, and output balance

public class Purchases {
public static void main(String[] args) {
    // output the information for Euros conversion
    Card.setRate(1.2128);
    System.out.println("rate = " + Card.getRate());
    System.out.println("1.00 euro is equal to "
     + Card.convertEurosToDollars(1.00) + " dollars.");

    // declaration and initialization of instance variables
    Card card;
    card = new Card(12345, 0.0);

    // purchase and output balance
    card.purchaseInDollars(100.00);
    System.out.println("after spending 100.00 dollars");
    System.out.print("card: Account Number = "
    + card.getAccountNum() + ", balance = ");
    System.out.printf("%.2f dollar",card.getBalance());
    System.out.println();

    // purchase and output balance
    card.purchaseInEuros(100.00);                 // See Exercise 5
    System.out.println("after spending 100.00 euros");
    System.out.print("card: Account Number = "
    + card.getAccountNum() + ", balance = ");
    System.out.printf("%.2f dollars",card.getBalance());
    System.out.println();
}
}

// definition of Card class

public class Card {
// data members
private static final int DEFAULT_ACCOUNT_NUMBER = 0;
private static final double DEFAULT_BALANCE = 0.0;
private static double rate;
private int accountNum;
private double balance;

// class methods
public static double convertEurosToDollars(double euros) {
    return euros*rate;
}

public static void setRate(double aRate) {
    rate = aRate;
}

public static double getRate() {
    return rate;
}

// constructors
public Card() {
    // using second constructor
    this(DEFAULT_ACCOUNT_NUMBER, DEFAULT_BALANCE);
}

public Card(int accountNum, double amount) {
    // using setAccountNum and purchaseInDollars methods
    setAccountNum(accountNum);
    balance = amount;
}

// mutator methods
public void setAccountNum(int accountNum) {
    this.accountNum = accountNum;
}

public void purchaseInDollars(double dollars) {
    balance += dollars;
}

public void purchaseInEuros(double euros) {
    balance += convertEurosToDollars(euros);
}

// accessor methods
public int getAccountNum() {
    return accountNum;
}

public double getBalance() {
    return balance;
}
}