Am not new to PHP but new to OOP, I have watched lot of tutorials for oop and as I saw, class is almost a new language!!
To be a pro programmer, I should learn existing class attributes or I should create my own??
example of default class attribute:
$dbh = new PDO("mysql:host=localhost;dbname=test","root","");
$sth = $dbh -> query("select * from page");
$result = $sth -> fetch();
example of my own classic class: