3v4l.org

run code in 300+ PHP versions simultaneously
<?php fscanf(STDIN, "%d", $n); $c = 0; for($i=1;$i<=$n;$i++) { if($i % 2 == 0 )continue; $c += substr_count($i, 1); } echo $c . "\n";
Output for 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.38, 7.0.0 - 7.0.33, 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, 8.1.0 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
0

preferences:
218.62 ms | 404 KiB | 364 Q