新特性

PHP 核心中的新特性

命名參數(shù)

新增命名參數(shù)的功能。

注解（Attributes）

新增注解的功能。

構(gòu)造器屬性提升（Constructor Property Promotion）

新增構(gòu)造器屬性提升功能 在構(gòu)造函數(shù)中聲明類的屬性）。

聯(lián)合類型

新增 聯(lián)合類型。

Match 表達(dá)式

新增 match 表達(dá)式。

Nullsafe 運(yùn)算符

新增Nullsafe 運(yùn)算符(?->)。

其他新特性

  • 新增 WeakMap 類。

  • 新增 ValueError 類。

  • 現(xiàn)在，只要類型兼容，任意數(shù)量的函數(shù)參數(shù)都可以用一個(gè)可變參數(shù)替換。 例如允許編寫下面的代碼：

    <?php
    class A {
         public function     method(int $many, string $parameters, $here) {}
    }
    class     B extends A {
         public function     method(...$everything) {}
    }
    ?>

  • static ("后期靜態(tài)綁定"中) 可以作為返回類型：

    <?php
    class Test {
         public function     create(): static {
              return new static();
         }
    }
    ?>

  • 現(xiàn)在可以通過(guò) $object::class 獲取類名，返回的結(jié)果和 get_class($object) 一致。

  • new、instanceof 可用于任何表達(dá)式， 用法為 new (expression)(...$args) 和 $obj instanceof (expression)。

  • 添加對(duì)一些變量語(yǔ)法一致性的修復(fù)，例如現(xiàn)在能夠編寫 Foo::BAR::$baz。

  • 添加 Stringable interface， 當(dāng)一個(gè)類定義 __toString() 方法后會(huì)自動(dòng)實(shí)現(xiàn)該接口。

  • Trait 可以定義私有抽象方法（abstract private method）。 類必須實(shí)現(xiàn) trait 定義的該方法。

  • 可作為表達(dá)式使用 throw。 使得可以編寫以下用法：

    <?php
    $fn     = fn() => throw new Exception('Exception in arrow function');
    $user = $session->user ?? throw new Exception('Must have user');

  • 參數(shù)列表中的末尾逗號(hào)為可選。

    <?php
    function functionWithLongSignature(
            Type1 $parameter1,
            Type2 $parameter2, // <-- 這個(gè)逗號(hào)也被允許了
    ) {
    }

  • 現(xiàn)在允許 catch (Exception) 一個(gè) exception 而無(wú)需捕獲到變量中。

  • 支持 mixed 類型。

  • Private methods declared on a parent class no longer enforce any inheritance rules on the methods of a child class (with the exception of final private constructors). The following example illustrates which restrictions have been removed:

    <?php
    class ParentClass {
        private function     method1() {}
        private function     method2() {}
        private static function     method3() {}
            // Throws a warning, as "final" no longer has an effect:
            private final function method4() {}
    }
    class     ChildClass extends ParentClass {
            // All of the following are now allowed, even though the modifiers aren't
        // the same as for the private methods in the parent class.
            public abstract function method1() {}
        public static function     method2() {}
        public function     method3() {}
        public function     method4() {}
    }
    ?>

  • get_resource_id() has been added, which returns the same value as (int) $resource. It provides the same functionality under a clearer API.

Date and Time

DOM

DOMParentNode and DOMChildNode with new traversal and manipulation APIs have been added.

Filter

FILTER_VALIDATE_BOOL has been added as an alias for FILTER_VALIDATE_BOOLEAN. The new name is preferred, as it uses the canonical type name.

Enchant

enchant_dict_add(), enchant_dict_is_added(), and LIBENCHANT_VERSION have been added.

FPM

Added a new option pm.status_listen that allows getting the status from different endpoint (e.g. port or UDS file) which is useful for getting the status when all children are busy with serving long running requests.

Hash

HashContext objects can now be serialized.

Internationalization Functions

The IntlDateFormatter::RELATIVE_FULL, IntlDateFormatter::RELATIVE_LONG, IntlDateFormatter::RELATIVE_MEDIUM, and IntlDateFormatter::RELATIVE_SHORT constants have been added.

LDAP

ldap_count_references() has been added, which returns the number of reference messages in a search result.

OPcache

If the opcache.record_warnings ini setting is enabled, OPcache will record compile-time warnings and replay them on the next include, even if it is served from cache.

OpenSSL

Added Cryptographic Message Syntax (CMS) (? RFC 5652) support composed of functions for encryption, decryption, signing, verifying and reading. The API is similar to the API for PKCS #7 functions with an addition of new encoding constants: OPENSSL_ENCODING_DER, OPENSSL_ENCODING_SMIME and OPENSSL_ENCODING_PEM:

  • openssl_cms_encrypt() encrypts the message in the file with the certificates and outputs the result to the supplied file.
  • openssl_cms_decrypt() that decrypts the S/MIME message in the file and outputs the results to the supplied file.
  • openssl_cms_read() that exports the CMS file to an array of PEM certificates.
  • openssl_cms_sign() that signs the MIME message in the file with a cert and key and output the result to the supplied file.
  • openssl_cms_verify() that verifies that the data block is intact, the signer is who they say they are, and returns the certs of the signers.

Regular Expressions (Perl-Compatible)

preg_last_error_msg() has been added, which returns a human-readable message for the last PCRE error. It complements preg_last_error(), which returns an integer enum value instead.

Reflection

SQLite3

SQLite3::setAuthorizer() and respective class constants have been added to set a userland callback that will be used to authorize or not an action on the database.

Standard Library

  • str_contains(), str_starts_with() and str_ends_with() have been added, which check whether haystack contains, starts with or ends with needle, respectively.

  • fdiv() has been added, which performs a floating-point division under IEEE 754 semantics. Division by zero is considered well-defined and will return one of Inf, -Inf or NaN.

  • get_debug_type() has been added, which returns a type useful for error messages. Unlike gettype(), it uses canonical type names, returns class names for objects, and indicates the resource type for resources.

  • printf() and friends now support the %h and %H format specifiers. These are the same as %g and %G, but always use "." as the decimal separator, rather than determining it through the LC_NUMERIC locale.

  • printf() and friends now support using "*" as width or precision, in which case the width/precision is passed as an argument to printf. This also allows using precision -1 with %g, %G, %h and %H. For example, the following code can be used to reproduce PHP's default floating point formatting:

    <?php
    printf    ("%.*H", (int) ini_get("precision"), $float);
    printf("%.*H", (int) ini_get("serialize_precision"), $float);
    ?>

  • proc_open() now supports pseudo-terminal (PTY) descriptors. The following attaches stdin, stdout and stderr to the same PTY:

    <?php
    $proc     = proc_open($command, [['pty'], ['pty'], ['pty']], $pipes);
    ?>

  • proc_open() now supports socket pair descriptors. The following attaches a distinct socket pair to stdin, stdout and stderr:

    <?php
    $proc     = proc_open($command, [['socket'], ['socket'], ['socket']], $pipes);
    ?>

    Unlike pipes, sockets do not suffer from blocking I/O issues on Windows. However, not all programs may work correctly with stdio sockets.

  • Sorting functions are now stable, which means that equal-comparing elements will retain their original order.

  • array_diff(), array_intersect() and their variations can now be used with a single array as argument. This means that usages like the following are now possible:

    <?php
    // OK even if $excludes is empty:
    array_diff($array, ...$excludes);
    // OK even if $arrays only contains a single array:
    array_intersect(...$arrays);
    ?>

  • The flag parameter of ob_implicit_flush() was changed to accept a bool rather than an int.

Tokenizer

PhpToken adds an object-based interface to the tokenizer. It provides a more uniform and ergonomic representation, while being more memory efficient and faster.

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