(PHP 5 >= 5.1.0, PHP 7)
Serializable::serialize — String representation of object
Should return the string representation of the object.
Notă:
This method acts as the destructor of the object. The __destruct() method will not be called after this method.
Această funcție nu are parametri.
Returns the string representation of the object or NULL
Throws Exception when returning other types than strings and
NULL
.