(PECL weakref >= 0.1.0)
Weakref::__construct — Constructs a new weak reference
$object
)Constructs a new weak reference.
objectThe object to reference.
没有返回值。
Example #1 Weakref::__construct() example
<?php
class MyClass {
public function __destruct() {
echo "Destroying object!\n";
}
}
$o1 = new MyClass;
$r1 = new Weakref($o1);
if ($r1->valid()) {
echo "Object still exists!\n";
var_dump($r1->get());
} else {
echo "Object is dead!\n";
}
unset($o1);
if ($r1->valid()) {
echo "Object still exists!\n";
var_dump($r1->get());
} else {
echo "Object is dead!\n";
}
?>
以上例程会输出：
Object still exists!
object(MyClass)#1 (0) {
}
Destroying object!
Object is dead!