main.php of PHP OOP Tutorial 2

main.php

<?php
//Object Oriented Programming in PHP Intro #2
class bank {
    private $name = '';
    public function __construct($name) {
        echo "Starting the bank: $name.";
        $this->name=$name;
    }
    public function iHaveThisMuchMoney(){
        $sum = 0;
        foreach($this->accounts as $account){
            if($account instanceof account){
                $sum += $account->getMoney();
            }
        }
        return $sum;
    }
    private $accounts = array();
    private $special = array();
    public function addAccount(account $account){
        if($account instanceof account){
            $this->accounts[] = $account;
        }
        if($account instanceof specialAccount){
            $this->special[] = $account;
        }
    }
    public function prefered($account){
        return in_array($account, $this->special);
    }
    public function getAccountFromID($id){
        foreach($this->accounts as $account){
            if($account instanceof account){
                if($account->myID()==$id){
                    return $account;
                }   
            }
        }
        return null;//Sorry, not in mah bank.
    }
}
class account {
    private static $instanceID = 0;
    private $id = -1;
    public function __construct() {
        $this->id=self::$instanceID;
        self::$instanceID+=1;//Prepare the next ID for the next account
    }
    private $money = 0;
    public function deposit($moneys){
        $this->money = $moneys;
    }
    public function withdraw($money){
        if($money <= $this->money){
            $this->money -=$money;
            return true;
        }
        return false;
    }
    public function getMoney(){
        return $this->money;
    }
    public function myID(){
        return $this->id;
    }
}
class specialAccount extends account {
    
}
$bank = new bank('Toad');
echo "\n";
echo "I have this much money: ".$bank->iHaveThisMuchMoney()."\n";
$acc1 = new account();
$acc1->deposit(42.13);
echo "some new account has ".$acc1->getMoney()."\n";
$acc2 = new account();
$acc2->deposit(13.42);
$acc3 = new specialAccount();
$acc3->deposit(22.22);

$bank->addAccount($acc1);
$bank->addAccount($acc2);
$bank->addAccount($acc3);
echo "I have this much money: ".$bank->iHaveThisMuchMoney()."\n";
echo "Is account 3 a prefered customer? ".(int)$bank->prefered($bank->getAccountFromID(1));

echo "\n";
?>