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serialize | PHP | Functions | serialize

Generates a storable representation of a value


serialize ( mixed $value ) : string



The value to be serialized. serialize() handles all types, except the resource-type and some objects (see note below). You can even serialize() arrays that contain references to itself. Circular references inside the array/object you are serializing will also be stored. Any other reference will be lost. When serializing objects, PHP will attempt to call the member functions __serialize() or __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 __unserialize() or __wakeup() member function is called.

Note: Object's private members have the class name prepended to the member name; protected members have a '*' prepended to the member name. These prepended values have null bytes on either side.


Returns a string containing a byte-stream representation of value that can be stored anywhere. Note that this is a binary string which may include null bytes, and needs to be stored and handled as such. For example, serialize() output should generally be stored in a BLOB field in a database, rather than a CHAR or TEXT field.



// $session_data contains a multi-dimensional array with session information for the current user. We use serialize() to store it in a database at the end of the request.

$conn = odbc_connect("webdb", "php", "chicken");
$stmt = odbc_prepare($conn, "UPDATE sessions SET data = ? WHERE id = ?");
$sqldata = array(serialize($session_data), $_SERVER['PHP_AUTH_USER']);

if (!odbc_execute($stmt, $sqldata)) {
    $stmt = odbc_prepare($conn, "INSERT INTO sessions (id, data) VALUES(?, ?)");
    if (!odbc_execute($stmt, $sqldata)) {
        // something went wrong...