匿名函数参数信息不正确

Question

I need to write code according to the parameters of an anonymous function. The following code gives the parameters correctly.

Example code 1:

class test{

}

$func = function($a, $b, test $t, $c = 'new') {
    echo 'test function ran'.PHP_EOL;
};

$info = new ReflectionFunction($func);

var_dump(
    $info->getName(), 
    $info->getNumberOfParameters(), 
    $info->getNumberOfRequiredParameters()
);

result var_dump

string(9) "{closure}"
int(4)
int(3)

The result is different when I change the parameter order. Do you have any information on this?

Example code 2:

class test{

}

$func = function($a, $b, $c = 'new', test $t ) {
    echo 'test function ran'.PHP_EOL;
};

$info = new ReflectionFunction($func);

var_dump(
    $info->getName(), 
    $info->getNumberOfParameters(), 
    $info->getNumberOfRequiredParameters()
);

result var_dump

string(9) "{closure}"
int(4)
int(4)

I am sorry, my English is not good. I hope I can tell.

--- UPDATE -- Thank you for the answers. I get it now.