How to replace YEAR and MONTH to the current figure?

The function is to display a randon image from the folder 2021/01 Since the time is changing every month, how to change it in the first line? To make 2021/01 display the current year and month? For example, next month it will change to <?php $randomdir = dir(‘wp-content/uploads/2021/02’);

<?php $randomdir = dir('wp-content/uploads/2021/01');
$count = 1;
$pattern="/(gif|jpg|jpeg|png)/";
while($file = $randomdir->read()) {
    $ext = pathinfo($file, PATHINFO_EXTENSION);
    if (preg_match($pattern, $ext)) {
        $imagearray[$count] = $file;
        $count++;
    }
}
$random = mt_rand(1, $count - 1); 
echo '<img src="wp-content/uploads/2021/01/'.$imagearray[$random].'" alt />';
?>

Answer

Use date function for the same.

$randomdir = dir('wp-content/uploads/' . date('Y/m'));