PHP :: Static function and variable

index.php

<?php

class Hello
{
    private static $greeting = 'Hello, direct static call';

    function __construct($string = 'Hello, construct call')
    {
        self::$greeting = $string;
    }

    private static function initialize()
    {
        self::$greeting .= ' is There!';

        self::newline();
    }

    private static function newline()
    {
        self::$greeting .= '<br />';
    }

    public static function greet()
    {
        static $num = 1; // will remember last value

    	self::initialize();
        echo $num++ . '. ' . self::$greeting;
    }

    public function non_static_function()
    {
        self::$greeting = 'Overrided! print from non static function';
    }
}

Hello::greet(); // Hello There!

$hello = new Hello();

$hello->greet();
$hello->non_static_function();
$hello->greet();

/** Output:
 * 1. Hello, direct static call is There!
 * 2. Hello, construct call is There!
 * 3. Overrided! print from non static function is There!
 */