Php uses serialize () and unserialize () to convert objects into super variables.

The original words and summary in the manual:
Description and case of php functions serialize () and unserialize. To change serialized strings back to PHP values, use unserialize (). Serialize () can process any type other than resource. Even serialize () contains arrays that point to its own reference. References in arrays/objects of serialize () will also be stored.
Serialize () returns a string that contains a byte stream that represents value and can be stored anywhere. This facilitates storing or passing PHP values without losing their types and structures.
To change serialized strings back to PHP values, use unserialize (). Serialize () can process any type other than resource. Even serialize () contains arrays that point to its own reference. References in arrays/objects of serialize () will also be stored.
When an object is serialized, PHP tries to call the member function _ sleep () of the object before the sequential action (). This allows objects to be cleared before being serialized. Similarly, when unserialize () is used to restore an object, the _ wakeup () member function is called.
Note: in PHP 3, object attributes will be serialized, but methods will be lost. PHP 4 breaks this restriction and can store attributes and methods at the same time. For more information, see the serialization object section of the class and object.
Serialize () and unserialize () are described in the php manual as follows:
Serialize-Generates a storable representation of a value
Serialize-generate a representation of a stored value
Unserialize-Creates a PHP value from a stored representation
Unserialize-create a PHP value from a stored Representation
Serialize, translated as "serialization, continuous", usually called "serialization"
This function is useful, especially when used with unserialize.
I think it is useful to store data in a database or record it in a file.
Of course, this type of data must be complex (neither complicated nor serialize is required, and I think at least it must be an array) and be non-"index or primary key" in the database ", of course, it is best to leave this database Field irrelevant to any search program in the system. Of course, the data after serialize can still be searched because the specific data is not encrypted or changed.

Instance: (it is easy to talk about objects only)
CPerson. php
[Php]
<? Php
Class Person
{
Public $ age;
 
Function _ construct ($ age)
{
$ This-> age = $ age;
}
 
Function walk ()
{
Echo "I'm walking ...! ";
}
 
}
?>

Test0.php saves the object here
[Html]
<? Php
Session_start ();
Include_once './CPerson. php ';
 
$ Person = new Person (22 );
$ B = serialize ($ person );
 
$ _ SESSION ["object"] = $ B;
 
?>

Test1.php Access Object
[Php]
<? Php
Session_start ();
Include_once './CPerson. php ';
$ P = $ _ SESSION ['object'];
$ A = unserialize ($ p );
$ A-> walk ();
Echo $ a-> age;
?>