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This article brings you a detailed introduction to the update content of PHP 7.3. It has certain reference value. Friends in need can refer to it. I hope it will be helpful to you.
PHP is still a strong competitor to other scripting languages, mainly due to the rapid updates of its core maintenance team.
Since the release of PHP 7.0, the community has witnessed the birth of many new features that have greatly improved the way developers apply PHP in their projects. Improving the performance and security of PHP applications is the main purpose of these improvements.
PHP recently achieved another milestone - the release of PHP 7.3. The new version brings some much-needed updates.
In this article, I will discuss the newPHP 7.3 featuresand updates. The good news is that you can install the new version yourself on your test server and check out the new features. But as the old saying goes, never use RC version updates on production servers as they may break your already live applications.
The following are some updates introduced in version 7.3 that greatly improve the performance ofPHP 7.3compared to previous versions.
Flexible Heredoc and Nowdoc syntax
Allow trailing commas in function calls
JSON_THROW_ON_ERROR
PCRE2 Migration
list() allocation reference
is_countable function
array_key_first(), array_key_last()
Argon2 password hashing enhancements
Deprecated and removed image2wbmp()
Deprecation and removal of case-insensitive constants
Same site cookies
FPM Updates
Improved file deletion under Windows
Let’s discuss each of the above updates one by one.
Heredoc and Nowdoc syntax can be of great help when using multi-line long strings. It requires that the end identifier should be the first string that appears on a new line.
// 除了这样: $query = <<Overall, this update proposes two improvements, as follows:
Support for indentation before closing identifiers
No longer forced line breaks after closing identifiers
In the above example, you can easily see these changes.
Tail commas are allowed in function calls
Append a trailing comma at the end of the parameter, element, and variable lists. Sometimes we need to pass a large number of elements in arrays and function calls (especially variable parameter functions). If a comma is missed, an error will be reported. In this case, the trailing comma is very useful. This feature is already allowed within arrays, and starting with PHP 7.2, the grouped namespace (
Grouped Namespaces
) syntax also supports trailing commas.use Foo\Bar\{ Foo, Bar, }; $foo = [ 'foo', 'bar', ];The trailing comma is very useful when a new value needs to be appended here. This is especially true within variadic functions such as
unset()
.unset( $foo, $bar, $baz, );At the same time, when you use the
compact()
function to pass a batch of variables to the template engine, this is also an example that can be used.echo $twig->render( 'index.html', compact( 'title', 'body', 'comments', ) );In some cases where continuous or grouped data needs to be constructed, the
array_merge()
function is often used to merge arrays. You can also use a trailing comma:$newArray = array_merge( $arrayOne, $arrayTwo, ['foo', 'bar'], );Likewise, you can use this feature when calling any method, function, or closure.
class Foo { public function __construct(...$args) { // } public function bar(...$args) { // } public function __invoke(...$args) { // } } $foo = new Foo( 'constructor', 'bar', ); $foo->bar( 'method', 'bar', ); $foo( 'invoke', 'bar', );JSON_THROW_ON_ERROR
To parse JSON response data, there are two functions
json_encode()
andjson_decode()
available. Unfortunately, none of them have proper error throwing behavior.json_encode
will only returnfalse
when it fails;json_decode
will returnnull
when it fails, andnull
can be used as Legal JSON value. The only way to get an error is to calljson_last_error()
orjson_last_error_msg()
, which will return machine-readable and human-readable global error status respectively.The solution proposed by this RFC is to add a new
JSON_THROW_ON_ERROR
constant to the JSON function to ignore the global error status. When an error occurs, the JSON function will throw aJsonException
exception. The exception message (message
) is the return value ofjson_last_error()
, and the exception code (code
) is the return value ofjson_last_error_msg()
. The following is a calling example:json_encode($data, JSON_THROW_ON_ERROR); json_decode("invalid json", null, 512, JSON_THROW_ON_ERROR); // 抛出 JsonException 异常Upgrade PCRE2
PHP uses PCRE as the regular expression engine. But starting from PHP 7.3, PCRE2 will show its talents as a new regular engine. Therefore, you need to migrate existing regular expressions to comply with PCRE2 rules. These rules are more intrusive than before. Please see the following example:
preg_match('/[\w-.]+/', '');This expression will fail to match in the new version of PHP and will not trigger a warning. Because PCRE2 is now strict, hyphens (
-
) must be moved to the end or escaped if they are to be matched instead of being used to represent a range.After updating to PCRE2 10.x, the following and more features are supported:
Relative back reference
\g{ 2}
( Equivalent to existing\g{-2}
)PCRE2 版本检查
(?(VERSION>=x)...)
(*NOTEMPTY)
和(*NOTEMPTY_ATSTART)
告知引擎勿返回空匹配
(*NO_JIT)
禁用 JIT 优化
(*LIMIT_HEAP=d)
限制堆大小为d
KB
(*LIMIT_DEPTH=d)
设置回溯深度限制为d
(*LIMIT_MATCH=d)
设置匹配数量限制为d
译者注:国内正则术语参差不一,「后向引用」——Back References
,又称「反向引用」、「回溯引用」等,此处参考 PHP 官方手册的中文译本。list() 赋值引用
PHP 中的 list() 现在可以赋值给引用,在当前版本中 list() 中赋值不能使用引用,在 PHP 7.3 中将允许使用引用,新改进的语法如下:
$array = [1, 2]; list($a, &$b) = $array;相当于
$array = [1, 2]; $a = $array[0]; $b =& $array[1];在 PHP 7.3 的变更中,我们还可以与 foreach() 方法一起嵌套使用
$array = [[1, 2], [3, 4]]; foreach ($array as list(&$a, $b)) { $a = 7; } var_dump($array);is_countable 函数
在 PHP 7.2 中,用 count() 获取对象和数组的数量。如果对象不可数,PHP 会抛出警告⚠️ 。所以需要检查对象或者数组是否可数。 PHP 7.3 提供新的函数 is_countable() 来解决这个问题。
该 RFC 提供新的函数 is_countable(),对数组类型或者实现了
Countable
接口的实例的变量返回 true 。之前:
if (is_array($foo) || $foo instanceof Countable) { // $foo 是可数的 }之后:
if (is_countable($foo)) { // $foo 是可数的 }array_key_first(), array_key_last()
当前版本的 PHP 允许使用
reset()
,end()
和key()
等方法,通过改变数组的内部指针来获取数组首尾的键和值。现在,为了避免这种内部干扰,PHP 7.3 推出了新的函数来解决这个问题:
$key = array_key_first($array);
获取数组第一个元素的键名
$key = array_key_last($array);
获取数组最后一个元素的键名让我们看一个例子:
// 关联数组的用法 $array = ['a' => 1, 'b' => 2, 'c' => 3]; $firstKey = array_key_first($array); $lastKey = array_key_last($array); assert($firstKey === 'a'); assert($lastKey === 'c'); // 索引数组的用法 $array = [1 => 'a', 2 => 'b', 3 => 'c']; $firstKey = array_key_first($array); $lastKey = array_key_last($array); assert($firstKey === 1); assert($lastKey === 3);译者注:array_value_first()
和array_value_last()
并没有通过 RFC 表决;因此 PHP 7.3 内仅提供了array_key_first()
以及array_key_last()
函数。
参考链接:https://wiki.php.net/rfc/arra...Argon2 和 Hash 密码加密性能增强
在PHP的早期版本中,我们增加了Argon2和哈希密码加密算法,这是一种使用哈希加密算法来保护密码的现代算法。它有三种不同的类型,Argon2i,Argon2d和Argon 2id。 我们针对Argon2i密码散列和基于密码的密钥生成进行了优化。 Argon2d性能更快,并使用依赖于内存的数据访问。 Argon2i使用与内存无关的数据访问。 Argon2id是Argon2i和Argon2d的混合体,使用依赖于数据和与数据独立的存储器访问的组合。
password_hash():
Argon2id现在是在paswword_ *函数中使用的推荐的Argon2变量。
具有自定义成员方法的名称的Argon2id与PASSWORD_ARGON2I的使用方法相同 password_hash('password',PASSWORD_ARGON2ID,['memory_cost'=> 1 << 17,'time_cost'=> 4,'threads'=> 2]);password_verify();
除了Argon2i之外,password_verify()函数也适用于Argon2id。
password_needs_rehash();
此函数也将接受Argon2id哈希值,如果任何变量成员发生变化,则返回true。
$hash = password_hash('password', PASSWORD_ARGON2ID); password_needs_rehash($hash, PASSWORD_ARGON2ID); // 返回假 password_needs_rehash($hash, PASSWORD_ARGON2ID, ['memory_cost' => 1<<17]); // 返回真废弃并移除 image2wbmp()
该函数能够将图像输出为 WBMP 格式。另一个名为
imagewbmp()
的函数也同样具备单色转换的作用。因此,出于重复原因,image2wbmp() 现已被废弃,你可使用imagewbmp()
代替它。此函数被弃用后,再次调用它将会触发已弃用警告。待后续此函数被移除后,再次调用它将会触发致命错误。废弃并移除大小写不敏感的常量
使用先前版本的 PHP,你可以同时使用大小写敏感和大小写不敏感的常量。但大小写不敏感的常量会在使用中造成一点麻烦。所以,为了解决这个问题,PHP 7.3 废弃了大小写不敏感的常量。
原先的情况是:
类常量始终为「大小写敏感」。
使用
const
关键字定义的全局常量始终为「大小写敏感」。注意此处仅仅是常量自身的名称,不包含命名空间名的部分,PHP 的命名空间始终为「大小写不敏感」。使用
define()
函数定义的常量默认为「大小写敏感」。使用
define()
函数并将第三个参数设为true
定义的常量为「大小写不敏感」。如今 PHP 7.3 提议废弃并移除以下用法:
In PHP 7.3: 废弃使用
true
作为define()
的第三个参数。In PHP 7.3: 废弃使用与定义时的大小写不一致的名称,访问大小写不敏感的常量。
true
、false
以及null
除外。同站点 Cookie
PHP 7.3 在建议在使用 cookies 时,增加同站点标志。这个 RFC 会影响4个系统函数。
setcookie
setrawcookie
session_set_cookie_params
session_get_cookie_params
这个影响会在两种情况下起作用。其中一种方式会添加函数的新参数
,另一种方式允许以数组形式的选项代替其他单独选项。bool setcookie( string $name [, string $value = "" [, int $expire = 0 [, string $path = "" [, string $domain = "" [, bool $secure = false [, bool $httponly = false ]]]]]] ) bool setcookie ( string $name [, string $value = "" [, int $expire = 0 [, array $options ]]] ) // 两种方式均可.FPM 更新
FastCGI 进程管理器也进行了更新,现在提供了新的方式来记录 FPM 日志。
log_limit: 设置允许的日志长度,可以超过 1024 字符。
log_buffering: 允许不需要额外缓冲去操作日志。
decorate _workers_output: 当启用了 catch_workers_output 时,系统会去禁用渲染输出。
改进 Windows 下的文件删除
如官方文档所述:
默认情况下,文件描述符以共享读、写、删除的方式去操作。 这很有效的去映射 POSIX 并允许去删除正在使用中的文件。但这并不是100%都是一样的,不同的平台可能仍存在一些差异。删除操作之后,文件目录仍存在直到所有的文件操作被关闭。
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