Initialization of static variables in php_PHP tutorial

PHP member variables can be initialized at the same time as they are declared, but they can only be initialized with scalars, for example:

class A {
public $f1 = 'xxxx';
static public $f2 = 100;
}

If you want to assign a variable to an object, it can only be initialized in the constructor, for example:

class A {
private $child;
public function __construct() {
$this->child = new B();
}
}

But there is nothing similar to the static constructor/static block in Java in PHP, so there is no appropriate time to initialize it. There are also solutions for shared members, for example:

class A {

class A {
static public $child;
}
A::$child = new B();

static public $child;

}

A::$child = new B();

There seems to be no clean way for private members, the only way is to do this:

class A {
static private $child;
static public initialize() {
self::$child = new B();
}
}
A::initialize();

class A { static private $child;

static public initialize() {

self::$child = new B(); } } A::initialize();

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PHP member variables can be initialized at the same time as they are declared, but they can only be initialized with scalars, for example: class A { public $f1 = 'xxxx'; static public $f2 = 100; } If you want to change...