新特性

PHP 核心中的新特性

属性添加限定类型

类的属性中现在支持添加指定的类型。

publicint $id;

publicstring $name;

}?>

上面的例子中，会强制要求 $user->id 只能为 int

类型，同时 $user->name 只能为 string 类型。

箭头函数

箭头函数 提供了一种更简洁的定义函数的方法。

$factor=10;$nums=array_map(fn($n) =>$n*$factor, [1,2,3,4]);// $nums = array(10, 20, 30, 40);?>

有限返回类型协变与参数类型逆变

以下代码将不会正常工作：

classBextendsA{}

classProducer{

public functionmethod():A{}

}

classChildProducerextendsProducer{

public functionmethod():B{}

}?>

只有在使用自动加载的情况下，才会有完整的差异支持。在一个文件内，只有非循环类型引用是可能的，因为在引用之前，所有的类都需要可用。

空合并运算符赋值

$array['key'] ??=computeDefault();// 等同于以下旧写法if (!isset($array['key'])) {$array['key'] =computeDefault();

}?>

数组展开操作

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

数值文字分隔符

数字文字可以在数字之间包含下划线。

6.674_083e-11;// float299_792_458;// decimal0xCAFE_F00D;// hexadecimal0b0101_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.

允许从 __toString() 抛出异常

现在允许从 __toString()

抛出异常。之前的版本，将会导致一个致命错误。新版本中，之前发生致命错误的代码，已经被转换为

Error 异常。

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

OPcache

新增 缓存预加载 特性。

Regular Expressions (Perl-Compatible)

The 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_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

SQLite3

Added SQLite3::lastExtendedErrorCode()

to fetch the last extended result code.

Added SQLite3::enableExtendedResultCodes($enable = true),

which will make

Standard

strip_tags() with array of tag names

strip_tags($str, '

')

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.

The new serialization mechanism supersedes the

Serializable interface,

which will be deprecated in the future.

Array merge functions without arguments

array_merge(...$arrays).

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

redirect and null descriptors.

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

argon2i(d) without libargon