PHP 類的靜態變量索引，php靜態變量索引

PHP 類的靜態變量索引，php靜態變量索引

直接上代碼

<?php
class example{
    public static $pa;
    public $pb;
    public function __construct(){
        $this->pb = ++self::$pa;
    }
}

$a = new example;
$b = new example;

echo $a->pb;
echo '<hr/>';
echo $b->pb;
?>

 本來想結果應該是

1
-----------------------------------------------------
1

可是我錯了，正確的結果是

1
----------------------------------------------------------------------------------
2

基礎沒學好，趕快補補