They are eight different special methods, and they are all optional.
_init | Class initialization. |
_exit | Class clean-up. |
_new | Object instanciation. |
_free | Object release. |
_next | Object or class enumeration. |
_get | Array read operator. |
_put | Array write operator. |
_call | Using the object or the class as a method. |
_unknown | Calling an unknown method or property. |