Online PHP editor | output for 0vT33

@ 2018-06-14T12:21:36Z

<?php

class A implements \JsonSerializable
{
    public $prop;

    public function jsonSerialize()
    {
        $obj = new stdClass;

        if ($this->prop) {
            $obj->prop = $this->prop;
        }

        return $obj;
    }
}

class B implements \JsonSerializable
{
    public $a;

    public function jsonSerialize()
    {
        $obj = new stdClass;

        if ($this->a) {
            $obj->a = $this->a;
        }

        return $obj;
    }
}

$a = new A;
$b = new B;
$b->a = $a;

var_dump(json_encode($b));

Output for 8.1.0 - 8.1.33, 8.2.0 - 8.2.29, 8.3.0 - 8.3.25, 8.4.1 - 8.4.12: Deprecated: Return type of A::jsonSerialize() should either be compatible with JsonSerializable::jsonSerialize(): mixed, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /in/0vT33 on line 7 Deprecated: Return type of B::jsonSerialize() should either be compatible with JsonSerializable::jsonSerialize(): mixed, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /in/0vT33 on line 23 string(8) "{"a":{}}"
Output for 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30: string(8) "{"a":{}}"

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