类型之后的数字在var_dump（object）PHP中意味着什么？ [重复]

For example, in the manual

<?php
    class C {}

    function getC(): C {
        return new C;
    }

    var_dump(getC());
?>

Output

object(C)#1 (0) {
}

What does #1, (0) mean?

</div>

The #X is the order of instantiation of the object and the (X) is the number of properties:

class C {
    public $a;
}
$a = new C;
$b = new C;

var_dump($b);  // instantiated second
var_dump($a);  // instantiated first

Yields #1 for the first instantiated object and #2 for the second and (1) for both since they have one property a:

object(C)#2 (1) {
  ["a"]=>
  NULL
}
object(C)#1 (1) {
  ["a"]=>
  NULL
}

#1 is a unique identifier for each object, to allow you to tell when the same object appears in multiple places in the output.

(0) is the number of properties of the object. Since C has no properties, it's zero in this case.