Usage examples of php functions serialize() and unserialize(), usage of sprintf function_PHP tutorial

Usage examples of php functions serialize() and unserialize(), usage of sprintf function

The examples in this article describe the usage of PHP functions serialize() and unserialize(). Share it with everyone for your reference. The specific method is as follows:

This example mainly describes the description and case of PHP functions serialize() and unserialize(). To convert a serialized string back into a PHP value, use unserialize(). serialize() can handle any type except resource. You can even serialize() arrays that contain references to themselves. References in the array/object you are serializing() will also be stored.

serialize() returns a string, which contains a byte stream representing value and can be stored anywhere. This facilitates storing or passing PHP values ​​without losing their type and structure.

If you want to change the serialized string back to PHP value, you can use unserialize(). serialize() can handle any type except resource. You can even serialize() arrays that contain references to themselves. References in the array/object you are serializing() will also be stored.

When serializing an object, PHP will attempt to call the object's member function __sleep() before the sequence action. This allows any cleanup operations to be done before the object is serialized. Similarly, when an object is restored using unserialize(), the __wakeup() member function will be called.

Note: In PHP 3, object properties will be serialized, but methods will be lost. PHP 4 breaks this limitation and can store both properties and methods. See the Serialized Objects section in Classes and Objects for more information.
The explanation of serialize() and unserialize() in the PHP manual is:

serialize — Generates a storable representation of a value
serialize — Produce a storable representation of a value
unserialize — Creates a PHP value from a stored representation
unserialize — Create a PHP value from a stored representation
serialize, translated as "serialize, make continuous", usually called "serialization"

This function is very useful, especially when used together with unserialize
I think the more useful place is when storing data in a database or recording it in a file
Of course, this kind of data must be relatively complex (not complicated and does not need to be serialized, I think it must be at least an array), and it must be a non-"index or primary key" in the database. Of course, it is best for this database field to be in the system and It has nothing to do with any search program. Of course, the data after serialization can still be searched, because the specific data has not been encrypted or changed

Copy code The code is as follows:

//Simpler
$array = array();
$array['key'] = 'website';
$array['value']='www.isoji.org';
$a = serialize($array);
echo $a;
unset($array);
$a = unserialize($a);
print_r($a);

//Declare a class
class dog {
var $name;
var $age;
var $owner;
function dog($in_name="unnamed",$in_age="0",$in_owner="unknown") {
$this->name = $in_name;
$this->age = $in_age;
$this->owner = $in_owner;
}
function getage() {
return ($this->age * 365);
}

function getowner() {
return ($this->owner);
}

function getname() {
return ($this->name);
}
}
//Instantiate this class
$ourfirstdog = new dog("Rover",12,"Lisa and Graham");
//Use the serialize function to convert this instance into a serialized string
$dogdisc = serialize($ourfirstdog);
print $dogdisc; //$ourfirstdog has been serialized into a string O:3:"dog":3:{s:4:"name";s:5:"Rover";s:3:"age";i :12;s:5:"owner";s:15:"Lisa and Graham";}
print '
';
/*
Here you can store the string $dogdisc anywhere such as session, cookie, database, php file
*/
//We unregister this class here
unset($ourfirstdog);
/* Restore operation */
/*
Here, read the string $dogdisc from where you store it, such as session, cookie, database, php file
*/

//We use unserialize() here to restore the serialized object
$pet = unserialize($dogdisc); //$pet at this time is already the previous $ourfirstdog object
//Get age and name attributes
$old = $pet->getage();
$name = $pet->getname();
//This class can continue to be used without instantiation at this time, and the attributes and values ​​​​are maintained in the state before serialization
print "Our first dog is called $name and is $old days old
";
print '
';
?>

I hope this article will be helpful to everyone’s PHP programming design.

Write the functions for serialization and deserialization of PHP variables, and give an application example

";print_r(unserialize ($new));?>serialize() Encode variables and their values ​​into text form
unserialize() Restore original variables

Have you any questions about the php serialize() and unserialize() methods?

$person1 = new ysr(25, 'yuanshao');
$person1 is an object. After serializing it, it just changes to another way of expression!
$person2 = unserialize($listInfo);
After restoring this object, it becomes an object!
This object originally has the getAge() and getName()
operation methods, you can use these methods!

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