<?php
$strokes = array();

$_POST = array("h1" => 1, "h2" => 2, "h3" => 3, "h4" => 0);

        $strokes_keys = array('h1', 'h2', 'h3', 'h4');

        foreach ($strokes_keys as $stroke) {
          if (isset($_POST[$stroke])) {
          	array_push($strokes, $_POST[$stroke]);
          	}
		}
        $counts = count($strokes);
        
        var_dump($strokes);
        var_dump($counts);