mirror of
https://github.com/sigmasternchen/php-doc-en
synced 2025-03-15 08:28:54 +00:00
459c0e1de4
git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@344750 c90b9560-bf6c-de11-be94-00142212c4b1
434 lines
10 KiB
XML
434 lines
10 KiB
XML
<?xml version="1.0" encoding="utf-8"?>
|
|
<!-- $Revision$ -->
|
|
|
|
<sect1 xml:id="migration71.new-features" xmlns:xlink="http://www.w3.org/1999/xlink">
|
|
<title>New features</title>
|
|
|
|
<sect2 xml:id="migration71.new-features.nullable-types">
|
|
<title>Nullable types</title>
|
|
|
|
<para>
|
|
Type declarations for parameters and return values can now be marked as
|
|
nullable by prefixing the type name with a question mark. This signifies
|
|
that as well as the specified type, &null; can be passed as an argument, or
|
|
returned as a value, respectively.
|
|
</para>
|
|
|
|
<informalexample>
|
|
<programlisting role="php">
|
|
<![CDATA[
|
|
<?php
|
|
|
|
function testReturn(): ?string
|
|
{
|
|
return 'elePHPant';
|
|
}
|
|
|
|
var_dump(testReturn());
|
|
|
|
function testReturn(): ?string
|
|
{
|
|
return null;
|
|
}
|
|
|
|
var_dump(testReturn());
|
|
|
|
function test(?string $name)
|
|
{
|
|
var_dump($name);
|
|
}
|
|
|
|
test('elePHPant');
|
|
test(null);
|
|
test();
|
|
]]>
|
|
</programlisting>
|
|
&example.outputs;
|
|
<screen>
|
|
<![CDATA[
|
|
string(10) "elePHPant"
|
|
NULL
|
|
string(10) "elePHPant"
|
|
NULL
|
|
Uncaught Error: Too few arguments to function test(), 0 passed in...
|
|
]]>
|
|
</screen>
|
|
</informalexample>
|
|
</sect2>
|
|
|
|
<sect2 xml:id="migration71.new-features.void-functions">
|
|
<title>Void functions</title>
|
|
|
|
<para>
|
|
A <type>void</type> return type has been introduced. Functions declared with
|
|
void as their return type must either omit their return statement altogether,
|
|
or use an empty return statement. &null; is not a valid return value for a
|
|
void function.
|
|
</para>
|
|
|
|
<informalexample>
|
|
<programlisting role="php">
|
|
<![CDATA[
|
|
<?php
|
|
function swap(&$left, &$right): void
|
|
{
|
|
if ($left === $right) {
|
|
return;
|
|
}
|
|
|
|
$tmp = $left;
|
|
$left = $right;
|
|
$right = $tmp;
|
|
}
|
|
|
|
$a = 1;
|
|
$b = 2;
|
|
var_dump(swap($a, $b), $a, $b);
|
|
]]>
|
|
</programlisting>
|
|
&example.outputs;
|
|
<screen>
|
|
<![CDATA[
|
|
null
|
|
int(2)
|
|
int(1)
|
|
]]>
|
|
</screen>
|
|
</informalexample>
|
|
|
|
<para>
|
|
Attempting to use a void function's return value simply evaluates to
|
|
&null;, with no warnings emitted. The reason for this is because warnings
|
|
would implicate the use of generic higher order functions.
|
|
</para>
|
|
</sect2>
|
|
|
|
<sect2 xml:id="migration71.new-features.symmetric-array-destructuring">
|
|
<title>Symmetric array destructuring</title>
|
|
|
|
<para>
|
|
The shorthand array syntax (<literal>[]</literal>) may now be used to
|
|
destructure arrays for assignments (including within
|
|
<literal>foreach</literal>), as an alternative to the existing
|
|
<function>list</function> syntax, which is still supported.
|
|
</para>
|
|
|
|
<informalexample>
|
|
<programlisting role="php">
|
|
<![CDATA[
|
|
<?php
|
|
$data = [
|
|
[1, 'Tom'],
|
|
[2, 'Fred'],
|
|
];
|
|
|
|
// list() style
|
|
list($id1, $name1) = $data[0];
|
|
|
|
// [] style
|
|
[$id1, $name1] = $data[0];
|
|
|
|
// list() style
|
|
foreach ($data as list($id, $name)) {
|
|
// logic here with $id and $name
|
|
}
|
|
|
|
// [] style
|
|
foreach ($data as [$id, $name]) {
|
|
// logic here with $id and $name
|
|
}
|
|
]]>
|
|
</programlisting>
|
|
</informalexample>
|
|
</sect2>
|
|
|
|
<sect2 xml:id="migration71.new-features.class-constant-visibility">
|
|
<title>Class constant visibility</title>
|
|
|
|
<para>
|
|
Support for specifying the visibility of class constants has been added.
|
|
</para>
|
|
|
|
<informalexample>
|
|
<programlisting role="php">
|
|
<![CDATA[
|
|
<?php
|
|
class ConstDemo
|
|
{
|
|
const PUBLIC_CONST_A = 1;
|
|
public const PUBLIC_CONST_B = 2;
|
|
protected const PROTECTED_CONST = 3;
|
|
private const PRIVATE_CONST = 4;
|
|
}
|
|
]]>
|
|
</programlisting>
|
|
</informalexample>
|
|
</sect2>
|
|
|
|
<sect2 xml:id="migration71.new-features.iterable-pseudo-type">
|
|
<title><type>iterable</type> pseudo-type</title>
|
|
|
|
<para>
|
|
A new pseudo-type (similar to <type>callable</type>) called
|
|
<type>iterable</type> has been introduced. It may be used in parameter
|
|
and return types, where it accepts either arrays or objects that implement
|
|
the <classname>Traversable</classname> interface. With respect to subtyping,
|
|
parameter types of child classes may broaden a parent's declaration of <type>array</type>
|
|
or <classname>Traversable</classname> to <type>iterable</type>. With return types,
|
|
child classes may narrow a parent's return type of <type>iterable</type> to
|
|
<type>array</type> or an object that implements <classname>Traversable</classname>.
|
|
</para>
|
|
|
|
<informalexample>
|
|
<programlisting role="php">
|
|
<![CDATA[
|
|
<?php
|
|
function iterator(iterable $iter)
|
|
{
|
|
foreach ($iter as $val) {
|
|
//
|
|
}
|
|
}
|
|
]]>
|
|
</programlisting>
|
|
</informalexample>
|
|
</sect2>
|
|
|
|
<sect2 xml:id="migration71.new-features.mulit-catch-exception-handling">
|
|
<title>Multi catch exception handling</title>
|
|
|
|
<para>
|
|
Multiple exceptions per catch block may now be specified using the pipe
|
|
character (<literal>|</literal>). This is useful for when different
|
|
exceptions from different class hierarchies are handled the same.
|
|
</para>
|
|
|
|
<informalexample>
|
|
<programlisting role="php">
|
|
<![CDATA[
|
|
<?php
|
|
try {
|
|
// some code
|
|
} catch (FirstException | SecondException $e) {
|
|
// handle first and second exceptions
|
|
}
|
|
]]>
|
|
</programlisting>
|
|
</informalexample>
|
|
</sect2>
|
|
|
|
<sect2 xml:id="migration71.new-features.support-for-keys-in-list">
|
|
<title>Support for keys in <function>list</function></title>
|
|
|
|
<para>
|
|
You can now specify keys in <function>list</function>, or its new shorthand
|
|
<literal>[]</literal> syntax. This enables destructuring of arrays with
|
|
non-integer or non-sequential keys.
|
|
</para>
|
|
|
|
<informalexample>
|
|
<programlisting role="php">
|
|
<![CDATA[
|
|
<?php
|
|
$data = [
|
|
["id" => 1, "name" => 'Tom'],
|
|
["id" => 2, "name" => 'Fred'],
|
|
];
|
|
|
|
// list() style
|
|
list("id" => $id1, "name" => $name1) = $data[0];
|
|
|
|
// [] style
|
|
["id" => $id1, "name" => $name1] = $data[0];
|
|
|
|
// list() style
|
|
foreach ($data as list("id" => $id, "name" => $name)) {
|
|
// logic here with $id and $name
|
|
}
|
|
|
|
// [] style
|
|
foreach ($data as ["id" => $id, "name" => $name]) {
|
|
// logic here with $id and $name
|
|
}
|
|
]]>
|
|
</programlisting>
|
|
</informalexample>
|
|
</sect2>
|
|
|
|
<sect2 xml:id="migration71.new-features.support-for-negative-string-offsets">
|
|
<title>Support for negative string offsets</title>
|
|
|
|
<para>
|
|
Support for negative string offsets has been added to the
|
|
<link linkend="book.strings">string manipulation functions</link>
|
|
accepting offsets, as well as to
|
|
<link linkend="language.types.string.substr">string indexing</link> with
|
|
<literal>[]</literal> or <literal>{}</literal>. In such cases, a negative
|
|
offset is interpreted as being an offset from the end of the string.
|
|
</para>
|
|
|
|
<informalexample>
|
|
<programlisting role="php">
|
|
<![CDATA[
|
|
<?php
|
|
var_dump("abcdef"[-2]);
|
|
var_dump(strpos("aabbcc", "b", -3));
|
|
]]>
|
|
</programlisting>
|
|
&example.outputs;
|
|
<screen>
|
|
<![CDATA[
|
|
string (1) "e"
|
|
int(3)
|
|
]]>
|
|
</screen>
|
|
</informalexample>
|
|
|
|
<para>
|
|
Negative string and array offsets are now also supported in the simple
|
|
variable parsing syntax inside of strings.
|
|
</para>
|
|
|
|
<informalexample>
|
|
<programlisting role="php">
|
|
<![CDATA[
|
|
<?php
|
|
$string = 'bar';
|
|
echo "The last character of '$string' is '$string[-1]'.\n";
|
|
?>
|
|
]]>
|
|
</programlisting>
|
|
&example.outputs;
|
|
<screen>
|
|
<![CDATA[
|
|
The last character of 'bar' is 'r'.
|
|
]]>
|
|
</screen>
|
|
</informalexample>
|
|
</sect2>
|
|
|
|
<sect2 xml:id="migration71.new-features.support-for-aead-in-ext-openssl">
|
|
<title>Support for AEAD in ext/openssl</title>
|
|
|
|
<para>
|
|
Support for AEAD (modes GCM and CCM) have been added by extending the
|
|
<function>openssl_encrypt</function> and
|
|
<function>openssl_decrypt</function> functions with additional parameters.
|
|
</para>
|
|
</sect2>
|
|
|
|
<sect2 xml:id="migration71.new-features.convert-callables-to-closures">
|
|
<title>Convert callables to <classname>Closure</classname>s with <methodname>Closure::fromCallable</methodname></title>
|
|
|
|
<para>
|
|
A new static method has been introduced to the <classname>Closure</classname>
|
|
class to allow for <type>callable</type>s to be easily converted into
|
|
<classname>Closure</classname> objects.
|
|
</para>
|
|
|
|
<informalexample>
|
|
<programlisting role="php">
|
|
<![CDATA[
|
|
<?php
|
|
class Test
|
|
{
|
|
public function exposeFunction()
|
|
{
|
|
return Closure::fromCallable([$this, 'privateFunction']);
|
|
}
|
|
|
|
private function privateFunction($param)
|
|
{
|
|
var_dump($param);
|
|
}
|
|
}
|
|
|
|
$privFunc = (new Test)->exposeFunction();
|
|
$privFunc('some value');
|
|
]]>
|
|
</programlisting>
|
|
&example.outputs;
|
|
<screen>
|
|
<![CDATA[
|
|
string(10) "some value"
|
|
]]>
|
|
</screen>
|
|
</informalexample>
|
|
</sect2>
|
|
|
|
<sect2 xml:id="migration71.new-features.asynchronous-signal-handling">
|
|
<title>Asynchronous signal handling</title>
|
|
|
|
<para>
|
|
A new function called <function>pcntl_async_signals</function> has been
|
|
introduced to enable asynchronous signal handling without using ticks (which
|
|
introduce a lot of overhead).
|
|
</para>
|
|
|
|
<informalexample>
|
|
<programlisting role="php">
|
|
<![CDATA[
|
|
<?php
|
|
pcntl_async_signals(true); // turn on async signals
|
|
|
|
pcntl_signal(SIGHUP, function($sig) {
|
|
echo "SIGHUP\n";
|
|
});
|
|
|
|
posix_kill(posix_getpid(), SIGHUP);
|
|
]]>
|
|
</programlisting>
|
|
&example.outputs;
|
|
<screen>
|
|
<![CDATA[
|
|
SIGHUP
|
|
]]>
|
|
</screen>
|
|
</informalexample>
|
|
</sect2>
|
|
|
|
<sect2 xml:id="migration71.new-features.http2-server-push-support-in-ext-curl">
|
|
<title>HTTP/2 server push support in ext/curl</title>
|
|
|
|
<para>
|
|
Support for server push has been added to the CURL extension (requires
|
|
version 7.46 and above). This can be leveraged through the
|
|
<function>curl_multi_setopt</function> function with the new
|
|
<constant>CURLMOPT_PUSHFUNCTION</constant> constant. The constants
|
|
<constant>CURL_PUSH_OK</constant> and <constant>CURL_PUSH_DENY</constant> have also been
|
|
added so that the execution of the server push callback can either be
|
|
approved or denied.
|
|
</para>
|
|
</sect2>
|
|
|
|
<sect2 xml:id="migration71.new-features.stream-context-options">
|
|
<title>Stream Context Options</title>
|
|
|
|
<para>
|
|
The <link linkend="context.socket.tcp_nodelay">tcp_nodelay</link> stream
|
|
context option has been added.
|
|
</para>
|
|
</sect2>
|
|
|
|
</sect1>
|
|
|
|
<!-- Keep this comment at the end of the file
|
|
Local variables:
|
|
mode: sgml
|
|
sgml-omittag:t
|
|
sgml-shorttag:t
|
|
sgml-minimize-attributes:nil
|
|
sgml-always-quote-attributes:t
|
|
sgml-indent-step:1
|
|
sgml-indent-data:t
|
|
indent-tabs-mode:nil
|
|
sgml-parent-document:nil
|
|
sgml-default-dtd-file:"~/.phpdoc/manual.ced"
|
|
sgml-exposed-tags:nil
|
|
sgml-local-catalogs:nil
|
|
sgml-local-ecat-files:nil
|
|
End:
|
|
vim600: syn=xml fen fdm=syntax fdl=2 si
|
|
vim: et tw=78 syn=sgml
|
|
vi: ts=1 sw=1
|
|
-->
|