如何总结一些回声并显示为另一个回声？

Question

我正在尝试制作一个Stableford高尔夫计分系统，在该系统中，球员输入他们的击球次数，这就是他们打进洞的击球次数。对于每个孔，都有一个单独的点。由于有9个洞，因此有9个单独得分。我已经可以使系统回显每个孔的每个点。现在，我遇到的问题是，如何对所有九个回波求和并显示总结果？

这是pointhole9的if else语句

    <?php
    if(isset($_POST['submit'])){
       $number9=$_POST["number9"];

      if ($number9 == "4") {
        echo "Points hole 9: <input type='number' name='pointhole9' 
    id='pointhole9' value='2'/>";
    } elseif ($number9 == "5") {
        echo "Points hole 9: <input type='number' name='pointhole9' 
    id='pointhole9' value='1'/>";
    } elseif ($number9 >="6") {
        echo "Points hole 9: <input type='number' name='pointhole9' 
    id='pointhole9' value='0'/>";
    } elseif ($number9 == "3") {
        echo "Points hole 9: <input type='number' name='pointhole9' 
    id='pointhole9' value='3'/>";
    } elseif ($number9 <= "2") {
        echo "Points hole 9: <input type='number' name='pointhole9' 
    id='pointhole9' value='4'/>";
    }
    }
    ?>

这就是我试图将回声加起来的方式

    <?php
    if(isset($_POST['submit'])){
    $pointhole1 =$_POST['pointhole1'];
    $pointhole2 =$_POST['pointhole2'];
    $pointhole3 =$_POST['pointhole3'];
    $pointhole4 =$_POST['pointhole4'];
    $pointhole5 =$_POST['pointhole5'];
    $pointhole6 =$_POST['pointhole6'];
    $pointhole7 =$_POST['pointhole7'];
    $pointhole8 =$_POST['pointhole8'];
    $pointhole9 =$_POST['pointhole9'];

    $sum = 
  $pointhole1+$pointhole2+$pointhole3+$pointhole4+$pointhole5+
  $pointhole6+
  $pointhole7+$pointhole8+$pointhole9; 
    echo $sum;
  }
  ?>

使用if else语句，输出将有所不同。我只是在寻找如何汇总这些点孔。