<?php
class demo {
    public $a;
    public $b;
    public static $c = 100;
 
    public function __construct($a) {
        $this->a = $a;
        $this->funct();
    }
 
    public static function func() {
        $newObj = new self(20);
        $newObj->funct();
        self::$c += 100;
        echo self::$c;
    }
 
    private function funct() {
        $this->b = $this->a * 200;
    }
 
    public function getC() {
            echo  self::$c;
    }
}
 
$demo = new demo(3);
$demo::func();
$demo::getC();
$demo2 = new demo(4);
$demo2::func();
$demo::getC();
$demo2::getC();
$demo->getC();