PHP8.2 にはどのような変更が含まれますか (パフォーマンスの向上、新機能)!

file_get_contents(/* … */): string|false

function alwaysFalse(): false
{
    return false;
}

class Post
{
    public function getAuthor(): ?string { /* … */ }
}

class NullPost extends Post
{
    public function getAuthor(): null { /* … */ }
}

class Post
{
    public string $title;
}

// …

$post->name = 'Name';  // 在PHP8.2中不能这样使用，因为并没有在类中声明

class Post
{
    private array $properties = [];

    public function __set(string $name, mixed $value): void
    {
        $this->properties[$name] = $value;
    }
}

// …

$post->name = 'Name';

#[AllowDynamicProperties]
class Post
{
    public string $title;
}

// …

$post->name = 'Name'; // 一切正常

error_reporting(E_ALL ^ E_DEPRECATED);

function test(
    $foo,
    #[\SensitiveParameter] $bar,
    $baz
) {
    throw new Exception('Error');
}

test('foo', 'bar', 'baz');

Fatal error: Uncaught Exception: Error in test.php:8
Stack trace:
#0 test.php(11): test('foo', Object(SensitiveParameterValue), 'baz')
#1 {main}
  thrown in test.php on line 8

"self::method"
"parent::method"
"static::method"
["self", "method"]
["parent", "method"]
["static", "method"]
["Foo", "Bar::method"]
[new Foo, "Bar::method"]

if  ( $user -> admin )  {
   $restricted  =  false ;
}

if  ( $restricted )  {
   die ( '你没有进入这里的权限' ) ;
}

$name = 'Joe';
echo 'Welcome, ' . $naame;

if ($user->admin) {
   $restricted = false;
} else {
   $restrictedd = true;
}

if ($restricted) {
   die('You do not have permission to be here');
}

while ($item = $itr->next()) {

   $counter++; // 定义变量
}

  // 这里调用了变量，但是很有可能并没有定义这个变量
echo 'You scanned ' . $counter . ' items';

$restricted = true;
if ($user->admin) {
   $restricted = false;
}

if ($restricted) {
   die('You do not have permission to be here');
}

$counter = 0;
while ($item = $itr->next()) {
   $counter++;
}

echo 'You scanned ' . $counter . ' items';

readonly class Test {
    public string $prop;
}

readonly class Foo
{
    public int $bar;

    public function __construct() {
        $this->bar = 1;
    }
}

$foo = new Foo();
$foo->bar = 2;
// 抛出错误，不能修改只读属性 Foo::$bar

$foo->baz = 1;
// 抛出错误：不能动态创建属性 Foo::$baz

#[AllowDynamicProperties]
readonly class Foo {
}

readonly class Foo
{
    public $bar;
}
// 以上定义会产生错误。

readonly class Foo
{
    public static int $bar;
}
// 抛出错误: 只读属性不能声明静态类型