class test{
public static $a=1;
public $b=1;
public function a(){
self::$a++;
}public function b(){
$this->b++;}}
$x=new test();
$y=new test();
echo test::$a; //1
$x->a();echo test::$a //2
$y->a();echo test::$a //3
echo $x->b; //1
$x->b();echo $x->b; //2
$y->b();echo $x->b; //2