PHP Conference Nagoya 2025

Serializable::serialize

(PHP 5 >= 5.1.0, PHP 7, PHP 8)

Serializable::serializeReprésentation linéaire de l'objet

Description

public Serializable::serialize(): ?string

Retourne la représentation en chaîne de caractères de l'objet.

Liste de paramètres

Cette fonction ne contient aucun paramètre.

Valeurs de retour

Retourne la représentation de l'objet en chaîne de caractères, ou bien null.

Erreurs / Exceptions

Émet une Exception si un autre type que chaîne de caractères ou null est retourné.

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User Contributed Notes 2 notes

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20
crog at gustavus dot edu
11 years ago
The documentation here is somewhat misleading. Where it says "This method acts as the destructor of the object. The __destruct() method will not be called after this method," I believe the intent is not that the destructor is not run on the object itself, but that the destructor is not called /as part of the serialization process/.

That is, the object will still be destructed as it goes out of scope as normal, but the destructor is not called as a part of the object's serialization.
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4
John
7 years ago
I don't like the bad docs here, which are wrongly claiming that "serialize(): This method acts as the destructor of the object. The __destruct() method will not be called after this method.".

They are simply meaning that serialize() will NOT call __destruct(). That is the ONLY thing they mean.

Your object that is being serialized will continue to live as a normal object. So you should NOT treat serialize() as your destructor! Treat your object as a still-living copy that the user may be using!

The destructor will always run as normal, later, when your object goes out of scope (or is forcibly unset() by you)).

Example with proof:

<?php

class A implements Serializable
{
public
$data = [];

public function
__destruct()
{
echo
"Destruct of A called.\n";
}

public function
serialize()
{
printf("- Serialize of %s called.\n", static::class);
return
serialize($this->data);
}

public function
unserialize($serialized)
{
printf("- Unserialize of %s called.\n", static::class);
$this->data = unserialize($serialized);
}
}

class
B extends A
{
public function
__destruct()
{
echo
"Destruct of B called.\n";
}
}

$a = new A();
$a->data['inner_b'] = new B();
var_dump($a);

echo
"-----------------\n";
echo
"Calling serialize($a):\n";
$str = serialize($a);
echo
"-----------------\n";
echo
"End of script shutdown from here on:...\n";

?>

Result:

```
object(A)#1 (1) {
["data"]=>
array(1) {
["inner_b"]=>
object(B)#2 (1) {
["data"]=>
array(0) {
}
}
}
}
-----------------
Calling serialize($a):
- Serialize of A called.
- Serialize of B called.
-----------------
End of script shutdown from here on:...
Destruct of A called.
Destruct of B called.
```
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