PHP/while()

sample1
01234
sample1code
$i = 0;
while($i < 5){
  print_r($i);
  $i++;
}
sample2
sample2code
$number = 1;
            while($number <= 30) {
                echo 'option value="', $number, '">', $number. "名", '/option>';
                $number++;
            }