新特性

PHP 核心中的新特性

屬性添加限定類型

類的屬性中現(xiàn)在支持添加指定的類型。

<?php
class User {
    public 
int $id;
    public 
string $name;
}
?>
上面的例子中,會強制要求 $user->id 只能為 int 類型,同時 $user->name 只能為 string 類型。

箭頭函數(shù)

箭頭函數(shù) 提供了一種更簡潔的定義函數(shù)的方法。

<?php
$factor 
10;
$nums array_map(fn($n) => $n $factor, [1234]);
// $nums = array(10, 20, 30, 40);
?>

有限返回類型協(xié)變與參數(shù)類型逆變

以下代碼現(xiàn)在可以正常執(zhí)行:

<?php
class {}
class 
extends {}

class 
Producer {
    public function 
method(): {}
}
class 
ChildProducer extends Producer {
    public function 
method(): {}
}
?>
只有在使用自動加載的情況下,才會有完整的差異支持。在一個文件內(nèi),只有非循環(huán)類型引用是可能的,因為在引用之前,所有的類都需要可用。

空合并運算符賦值

<?php
$array
['key'] ??= computeDefault();
// 等同于以下舊寫法
if (!isset($array['key'])) {
    
$array['key'] = computeDefault();
}
?>

數(shù)組展開操作

<?php
$parts 
= ['apple''pear'];
$fruits = ['banana''orange', ...$parts'watermelon'];
// ['banana', 'orange', 'apple', 'pear', 'watermelon'];
?>

數(shù)值文字分隔符

數(shù)字文字可以在數(shù)字之間包含下劃線。

<?php
6.674_083e
-11// float
299_792_458;   // decimal
0xCAFE_F00D;   // hexadecimal
0b0101_1111;   // binary
?>

Weak references

Weak references allow the programmer to retain a reference to an object that does not prevent the object from being destroyed.

允許從 __toString() 拋出異常

現(xiàn)在允許從 __toString() 拋出異常。之前的版本,將會導(dǎo)致一個致命錯誤。新版本中,之前發(fā)生致命錯誤的代碼,已經(jīng)被轉(zhuǎn)換為 Error 異常。

CURL

CURLFile now supports stream wrappers in addition to plain file names, if the extension has been built against libcurl >= 7.56.0.

Filter

The FILTER_VALIDATE_FLOAT filter now supports the min_range and max_range options, with the same semantics as FILTER_VALIDATE_INT.

FFI

FFI is a new extension, which provides a simple way to call native functions, access native variables, and create/access data structures defined in C libraries.

GD

Added the IMG_FILTER_SCATTER image filter to apply a scatter filter to images.

Hash

Added crc32c hash using Castagnoli's polynomial. This CRC32 variant is used by storage systems, such as iSCSI, SCTP, Btrfs and ext4.

Multibyte String

Added the mb_str_split() function, which provides the same functionality as str_split(), but operating on code points rather than bytes.

OPcache

新增 緩存預(yù)加載 特性。

Regular Expressions (Perl-Compatible)

The preg_replace_callback() and preg_replace_callback_array() functions now accept an additional flags argument, with support for the PREG_OFFSET_CAPTURE and PREG_UNMATCHED_AS_NULL flags. This influences the format of the matches array passed to to the callback function.

PDO

The username and password can now be specified as part of the PDO DSN for the mysql, mssql, sybase, dblib, firebird and oci drivers. Previously this was only supported by the pgsql driver. If a username/password is specified both in the constructor and the DSN, the constructor takes precedence.

It is now possible to escape question marks in SQL queries to avoid them being interpreted as parameter placeholders. Writing ?? allows sending a single question mark to the database and e.g. use the PostgreSQL JSON key exists (?) operator.

PDO_OCI

PDOStatement::getColumnMeta() is now available.

PDO_SQLite

PDOStatement::getAttribute(PDO::SQLITE_ATTR_READONLY_STATEMENT) allows checking whether the statement is read-only, i.e. if it doesn't modify the database.

PDO::setAttribute(PDO::SQLITE_ATTR_EXTENDED_RESULT_CODES, true) enables the use of SQLite3 extended result codes in PDO::errorInfo() and PDOStatement::errorInfo().

SQLite3

Added SQLite3::lastExtendedErrorCode() to fetch the last extended result code.

Added SQLite3::enableExtendedResultCodes($enable = true), which will make SQLite3::lastErrorCode() return extended result codes.

Standard

strip_tags() with array of tag names

strip_tags() now also accepts an array of allowed tags: instead of strip_tags($str, '<a><p>') you can now write strip_tags($str, ['a', 'p']).

Custom object serialization

A new mechanism for custom object serialization has been added, which uses two new magic methods: __serialize and __unserialize.

<?php
// Returns array containing all the necessary state of the object.
public function __serialize(): array;

// Restores the object state from the given data array.
public function __unserialize(array $data): void;
?>
The new serialization mechanism supersedes the Serializable interface, which will be deprecated in the future.

Array merge functions without arguments

array_merge() and array_merge_recursive() may now be called without any arguments, in which case they will return an empty array. This is useful in conjunction with the spread operator, e.g. array_merge(...$arrays).

proc_open() function

proc_open() now accepts an array instead of a string for the command. In this case the process will be opened directly (without going through a shell) and PHP will take care of any necessary argument escaping.

<?php
proc_open
(['php''-r''echo "Hello World\n";'], $descriptors$pipes);
?>

proc_open() now supports redirect and null descriptors.

<?php
// Like 2>&1 on the shell
proc_open($cmd, [=> ['pipe''w'], => ['redirect'1]], $pipes);
// Like 2>/dev/null or 2>nul on the shell
proc_open($cmd, [=> ['pipe''w'], => ['null']], $pipes);
?>

argon2i(d) without libargon

password_hash() now has the argon2i and argon2id implementations from the sodium extension when PHP is built without libargon.