Magic Property

Special properties, which are not declared, but dynamically handled by the magic methods. They do not have specific declaration.

The magic methods to handle magic properties are : __get(), __set(), __isset() and __unset().

<?php

class x {
    //
    function __get($name) {
        return 'World!';
    }
}

$x = new x;
echo $x->hello; // display World!

?>

Documentation

Related : __get() method, __set() method