JAVA

/**

* A simple model for a consumer credit card.

* The task is to:

* 1. Understand and execute the code, then explain why the original Balance displayed for each card is different.

* 2. Modify the class to include a method that updates the credit limit. (2)

* 3. Use the method from Q2 to update the credit limit of the last CreditCard in the wallet to 3000 and display the new card summary

* 4. Modify the makePayment method so that it ignores requests to process a negative payment amount. (2)

* 5. Provide the code to test that your code for Q4 works as expected.

* 6. Modify the printSummary method to a non-static method and modify the main method code to work accordingly with this modification. (2)

* 7. Explain the difference between a static and a non-static method in a class.

* 8. Add a toString() method that returns a String representation of a CreditCard (instead of printing it to the console like printSummary). (2)

* - Use StringBuilder for this method

* 9. Print the details of the wallet again, using the standard println statement to print the String representation of each card.

*/

public class CreditCard {

// Instance variables:

private String customer; // name of the customer (e.g., "John Bowman")

private String bank; // name of the bank (e.g., "California Savings")

private String account; // account identifier (e.g., "5391 0375 9387 5309")

private int limit; // credit limit (measured in dollars)

protected double balance; // current balance (measured in dollars)

// Constructors:

/**

* Constructs a new credit card instance. This is a full-argument constructor

* @param cust the name of the customer (e.g., "John Bowman")

* @param bk the name of the bank (e.g., "California Savings")

* @param acnt the account identifier (e.g., "5391 0375 9387 5309")

* @param lim the credit limit (measured in dollars)

* @param initialBal the initial balance (measured in dollars)

*/

public CreditCard(String cust, String bk, String acnt, int lim, double initialBal) {

customer = cust;

bank = bk;

account = acnt;

limit = lim;

balance = initialBal;

}

/**

* Constructs a new credit card instance with default balance of zero.

* @param cust the name of the customer (e.g., "John Bowman")

* @param bk the name of the bank (e.g., "California Savings")

* @param acnt the account identifier (e.g., "5391 0375 9387 5309")

* @param lim the credit limit (measured in dollars)

*/

public CreditCard(String cust, String bk, String acnt, int lim) {

this(cust, bk, acnt, lim, 0.0); // use a balance of zero as default

}

// Accessor methods:

/** Returns the name of the customer. */

public String getCustomer() { return customer; }

/** Returns the name of the bank */

public String getBank() { return bank; }

/** Return the account identifier. */

public String getAccount() { return account; }

/** Return the credit limit. */

public int getLimit() { return limit; }

/** Return the current balance. */

public double getBalance() { return balance; }

// Update methods:

/**

* Charges the given price to the card, assuming sufficient credit limit.

* @param price the amount to be charged

* @return true if charge was accepted; false if charge was denied

*/

public boolean charge(double price) { // make a charge

if (price + balance > limit) // if charge would surpass limit

return false; // refuse the charge

// at this point, the charge is successful

balance += price; // update the balance

return true; // announce the good news

}

/**

* Processes customer payment that reduces balance.

* @param amount the amount of payment made

*/

public void makePayment(double amount) { // make a payment

balance -= amount;

}

// Utility method to print a card's information

public static void printSummary(CreditCard card) {

System.out.println("Customer = " + card.customer);

System.out.println("Bank = " + card.bank);

System.out.println("Account = " + card.account);

System.out.println("Balance = " + card.balance); // implicit cast

System.out.println("Limit = " + card.limit); // implicit cast

}

public static void main(String[] args) {

CreditCard[] wallet = new CreditCard[3];

wallet[0] = new CreditCard("John Bowman", "California Savings",

"5391 0375 9387 5309", 5000);

wallet[1] = new CreditCard("John Bowman", "California Federal",

"3485 0399 3395 1954", 3500);

wallet[2] = new CreditCard("John Bowman", "California Finance",

"5391 0375 9387 5309", 2500, 300);

for (int val = 1; val <= 16; val++) {

wallet[0].charge(3*val);

wallet[1].charge(2*val);

wallet[2].charge(val);

}

for (CreditCard card : wallet) {

CreditCard.printSummary(card); // calling static method

while (card.getBalance() > 200.0) {

card.makePayment(200);

System.out.println("New balance = " + card.getBalance());

}

System.out.println();

}

}

}