staircase.php

<?php

function StairCase($n) {
    for($i = 1; $i <= $n; $i++) {
        for($j = $n; $j >= 1; $j--) {
            echo ($j <= $i) ? "#" : " ";
        }
        
        echo "\n";
    }
}


Output:
    #
   ##
  ###
 ####
#####