serialize() returns a string containing a
byte-stream representation of
can be stored anywhere.
This is useful for storing or passing PHP values around without losing their type and structure.
To make the serialized string into a PHP value again, use unserialize(). serialize() handles all types, except the resource-type. You can even serialize() arrays that contain references to itself. Circular references inside the array/object you are serialize()ing will also be stored. Any other reference will be lost.
When serializing objects, PHP will attempt to call the member function __sleep() prior to serialization. This is to allow the object to do any last minute clean-up, etc. prior to being serialized. Likewise, when the object is restored using unserialize() the __wakeup() member function is called.
Note: This didn't work correctly until 4.0.7.
Note: In PHP 3, object properties will be serialized, but methods are lost. That limitation was removed in PHP 4 as both properties and methods are now restored. Please see the Serializing Objects section of Classes and Objects for more information.
It is not possible to serialize PHP built-in objects.
Example 1. serialize() example
See Also: unserialize().