(feat) Implement up to the end of Exercise 2

ie use Person in BankAccount, implement transferFunds(), demo those

week23.java

@@ -58,14 +58,14 @@ class DemoPerson {
 }
 
 class BankAccount {
-    private String name;
+    private Person person;
     private int accountNumber;
     private double balance;
 
     private static int nextAccountNumber = 0;
 
-    public BankAccount(String name) {
-        this.name = name;
+    public BankAccount(Person person) {
+        this.person = person;
         this.balance = 0.0;
         this.accountNumber = nextAccountNumber;
         nextAccountNumber++;
@@ -73,15 +73,15 @@ class BankAccount {
 
     @Override
     public String toString() {
-        return "BankAccount [name=" + name + ", accountNumber=" + accountNumber + ", balance=" + balance + "]";
+        return "BankAccount [person=" + person + ", accountNumber=" + accountNumber + ", balance=" + balance + "]";
     }
 
-    public int getAccountNumber() {
-        return accountNumber;
+    public Person getPerson() {
+        return person;
     }
 
-    public String getName() {
-        return name;
+    public int getAccountNumber() {
+        return accountNumber;
     }
 
     public double getBalance() {
@@ -94,9 +94,19 @@ class BankAccount {
 
     public void withdraw(double amount) {
         // No overdraft facilities here!
-        if (amount <= balance) {
+        // wait, reading ahead, there are...
+        // if (amount <= balance) {
             this.balance -= amount;
-        }
+            //}
+    }
+
+    /** Transfer funds out of the account to another {@link BankAccount}
+     * @param amount Amount to transfer
+     * @param recipient The lucky beneficiary
+     */
+    public void transferFunds(double amount, BankAccount recipient) {
+        this.withdraw(amount);
+        recipient.deposit(amount);
     }
 }
 
@@ -104,24 +114,53 @@ class BankAccount {
  * Exercise 2.4 & 2.6 - create two bank account objects and print their account
  * numbers, which should be 0 and 1.
  *
- * I forget the name for the implementation detail but a static member is shared across class objects / instances?
+ * Then 2.8 & 2.9 where we change it to use Person
  */
 class DemoBankAccount {
     public static void main(String[] args) {
-        BankAccount account1 = new BankAccount("Jerry");
-        BankAccount account2 = new BankAccount("Margo");
+        Person jerry = new Person();
+        jerry.setName("Jerry");
+        Person margo = new Person();
+        margo.setName("Margo");
+
+        BankAccount account1 = new BankAccount(jerry);
+        BankAccount account2 = new BankAccount(margo);
 
-        System.out.println(String.format("%s's account number: %d", account1.getName(), account1.getAccountNumber()));
-        System.out.println(String.format("%s's account number: %d", account2.getName(), account2.getAccountNumber()));
+        System.out.println(String.format("%s's account number: %d", account1.getPerson(), account1.getAccountNumber()));
+        System.out.println(String.format("%s's account number: %d", account2.getPerson(), account2.getAccountNumber()));
 
         System.out.println(String.format("Jerry will deposit £10, Margo will deposit £25"));
         account1.deposit(10.00);
         account2.deposit(25.00);
-        System.out.println(String.format("Accounts:\n\t%s\n\t%s", account1, account2));
+        System.out.println(String.format("Accounts:\n\t%s\n\t%s\n", account1, account2));
 
         System.out.println(String.format("Jerry goes to the pub and needs some cash for that. Margo goes to buy new garden furniture."));
         account1.withdraw(5.00);
         account2.withdraw(15.00);
         System.out.println(String.format("Accounts:\n\t%s\n\t%s", account1, account2));
+
+        System.out.println(".".repeat(80));
+        System.out.println(String.format("Now we're going to set up two accounts for the one person.\n"));
+        Person neighbour = new Person();
+        neighbour.setName("Tom");
+        BankAccount account3 = new BankAccount(neighbour);
+        BankAccount account4 = new BankAccount(neighbour);
+        System.out.println(String.format("Accounts:\n\t%s\n\t%s\n", account3, account4));
+
+        System.out.println(String.format("%s deposits some money in each.", neighbour));
+        account3.deposit(12.50);
+        account4.deposit(3.33);
+
+        System.out.println(String.format("Actually wait, the account wasn't set up in %s's name...", neighbour));
+        neighbour.setName("Barbara");
+        System.out.println(String.format("Accounts:\n\t%s\n\t%s\n", account3, account4));
+
+        System.out.println(".".repeat(80));
+        System.out.println(String.format("To help %s buy a new goat, %s lends them some money.",
+                                         neighbour, margo));
+        account2.transferFunds(10.00, account3);
+        System.out.println(String.format("Accounts:\n\t%s\n\t%s\n\t%s\n", account2, account3, account4));
     }
 }
+
+