1: <?php
 2: namespace Sotr\Crypto;
 3: 
 4: /**
 5:  * This class represents the current
 6:  * balance of different currencies in
 7:  * a given user account.
 8:  */
 9: class AccountBalance
10: {
11:     /**
12:      * The set of currencies and their
13:      * related balance.
14:      *
15:      * @var array
16:      */
17:     private $balance;
18: 
19:     /**
20:      * Constructs a new balance instance,
21:      * optionally with the provided starting
22:      * balance.
23:      *
24:      * @param   array   $balance
25:      */
26:     public function __construct(array $balance = [])
27:     {
28:         foreach ($balance as $currency => $value) {
29:             $this->set($currency, $value);
30:         }
31:     }
32: 
33:     /**
34:      * Returns the balance of the given
35:      * currency.
36:      *
37:      * @param   string  $currency
38:      * @return  float
39:      */
40:     public function get($currency)
41:     {
42:         return isset($this->balance[$currency]) ? $this->balance[$currency] : null;
43:     }
44: 
45:     /**
46:      * Sets the balance of the given currency.
47:      *
48:      * @param   string  $currency
49:      * @param   float   $value
50:      */
51:     public function set($currency, $value)
52:     {
53:         $this->balance[$currency] = $value;
54:     }
55: }
56: