PHP Manual: Deprecated Features

PHP Core

Implementing Serializable without serialize and unserialize

Either only the new methods should be implemented, if no support for PHP prior to version 7.4 is provided, or both should be implemented.

Passing `null` to non-nullable parameters of built-in functions

Scalar types for built-in functions are nullable by default. This behaviour is deprecated to align with the behaviour of user-defined functions, where scalar types need to be marked as nullable explicitly.

<?php
var_dump(str_contains("foobar", null));
// Deprecated: Passing null to parameter #2 ($needle) of type string
//             is deprecated
?>

Implicit incompatible float to int conversions

The implicit conversion of float to int which leads to a loss in precision is now deprecated. This affects array keys, int type declarations in coercive mode, and operators working on ints.

<?php
$a = [];
$a[15.5]; // deprecated, as key value loses the 0.5 component
$a[15.0]; // ok, as 15.0 == 15
?>

Calling a static element on a trait

Calling a static method, or accessing a static property directly on a trait is deprecated. Static methods and properties should only be accessed on a class using the trait.

Returning a non-array from __sleep

Returning a value which is not an array from __sleep() now generates a diagnostic.

Returning by reference from a void function

<?php
function &test(): void {}
?>

Such a function is contradictory, and already emits the following E_NOTICE when called: Only variable references should be returned by reference.

Autovivification from `false`

Autovivification is the process of creating a new array when appending to a value. Autovivification is prohibited from scalar values, false however was an exception. This is now deprecated.

<?php
$arr = false;
$arr[] = 2;   // deprecated
?>

Note:
Autovivification from null and undefined values is still allowed:
<?php
// From undefined
$arr[] = 'some value';
$arr['doesNotExist'][] = 2;
// From null
$arr = null;
$arr[] = 2;
?>

ctype

Verifying non-string arguments

Passing a non-string argument is deprecated. In the future, the argument will be interpreted as a string instead of an ASCII codepoint. Depending on the intended behavior, the argument should either be cast to string or an explicit call to chr should be made. All ctype_*() functions are affected.

Date

date_sunrise and date_sunset have been deprecated in favor of date_sun_info.

strptime has been deprecated. Use date_parse_from_format instead (for locale-independent parsing), or IntlDateFormatter::parse (for locale-dependent parsing).

strftime and gmstrftime have been deprecated. Use date instead (for locale-independent formatting), or IntlDateFormatter::format (for locale-dependent formatting).

Filter

The FILTER_SANITIZE_STRING and FILTER_SANITIZE_STRIPPED filters are deprecated.

The filter.default INI directive is deprecated.

GD

The num_points of imagepolygon, imageopenpolygon and imagefilledpolygon has been deprecated.

Hash

The mhash, mhash_keygen_s2k, mhash_count, mhash_get_block_size, and mhash_get_hash_name have been deprecated. Use the hash_*() functions instead.

IMAP

The NIL constant has been deprecated. Use 0 instead.

Intl

Calling IntlCalendar::roll with a bool argument is deprecated. Use 1 and -1 instead of true and false respectively.

Multibyte String

Calling mb_check_encoding without any arguments is deprecated.

MySQLi

The mysqli_driver::$driver_version property has been deprecated. It was meaningless and outdated, use PHP_VERSION_ID instead.

Calling mysqli::get_client_info or mysqli_get_client_info with the mysqli argument has been deprecated. Call mysqli_get_client_info without any arguments to obtain the version information of the client library.

The mysqli::init method has been deprecated. Replace calls to parent::init with parent::__construct.

OCI8

The oci8.old_oci_close_semantics INI directive is deprecated.

ODBC

odbc_result_all has been deprecated.

PDO

The PDO::FETCH_SERIALIZE fetch mode has been deprecated.

PgSQL

Not passing the connection argument to all pgsql_*() functions has been deprecated.

SOAP

The ssl_method option of SoapClient::__construct has been deprecated in favor of SSL stream context options.

Standard

Calling key, current, next, prev, reset, or end on objects is deprecated. Either convert the object to an array using get_mangled_object_vars first, or use the methods provided by a class that implements Iterator, such as ArrayIterator, instead.

The auto_detect_line_endings INI directive is deprecated. If necessary, handle "\r" line breaks manually instead.

The FILE_BINARY and FILE_TEXT constants have been deprecated. They never had any effect.

Deprecated Features