php - 如何允许用户添加另一个提交到 php 文件的输入行

Question

我制作了一个简单的 GPA(平均绩点)计算器，我只是在玩一些东西，并且真的很想知道如何允许用户随意添加行。我能找到的最好的例子是在这个网站上:http://gpacalculator.net/high-school-gpa-calculator/

我想我可能会理解，当用户单击按钮时，jquery 函数可以添加一行，但是我如何获取它，以便每次有人添加行时输入元素的名称都不同。 php 文件如何知道 $_POST['someName'].

简而言之，问题是:如何使用 jquery 添加一行，然后将该表单提交到 php 文件，以便它与预制的行不同。

以防万一您需要知道，我将发送到 php 文件的值存储在变量中。然后将它们输入到计算 GPA 的公式中。

编辑这里是表的代码:

<table>
    <form id = "myform" name = "myform" method = "POST" action = "">
        <tr> 
            <th> Grade in test </th> 
            <th> Weight of grade </th> <br />
         </tr>
        <tr> <td><input type = "text" name = "grade1" /> </td> <td> <input type = "text" name = "weight1"  /> </td> </tr>
        <tr> <td><input type = "text" name = "grade2" /> </td> <td> <input type = "text" name = "weight2"  /> </td> </tr>
        <tr> <td><input type = "text" name = "grade3" /> </td> <td> <input type = "text" name = "weight3"  /> </td> </tr>
        <tr> <td><input type = "text" name = "grade4" /> </td> <td> <input type = "text" name = "weight4"  /> </td> </tr>
        <tr> <td><input type = "text" name = "grade5" /> </td> <td> <input type = "text" name = "weight5"  /> </td> </tr>
        <tr> <td><input type = "text" name = "grade6" /> </td> <td> <input type = "text" name = "weight6"  /> </td> </tr>
        <tr> <td><input type = "text" name = "grade7" /> </td> <td> <input type = "text" name = "weight7"  /> </td> </tr>
        <tr> <td><input type = "text" name = "grade8" /> </td> <td> <input type = "text" name = "weight8"  /> </td> </tr>
        <tr> <td><input type = "text" name = "grade9" /> </td> <td> <input type = "text" name = "weight9"  /> </td> </tr>
        <tr> <td><input type = "text" name = "grade10" /> </td> <td> <input type = "text" name = "weight10"  /> </td> </tr>
        <tr> <td><input type = "text" name = "grade11" /> </td> <td> <input type = "text" name = "weight11"  /> </td> </tr>
        <tr> <td><input type = "text" name = "grade12" /> </td> <td> <input type = "text" name = "weight12"  /> </td> </tr>

<tr> 
  <td> <div id = "submitButton">
          <input type = "submit" value = "SUBMIT"  style = " font-family:'HelveticaNeue-Light', 'Helvetica Neue Light', 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; padding: 10px;border: none; color: white; background-color: #0499ff; width: 100%; font-size: 13px; border-radius: 5px;""/></div></td> <td> <input type = "reset"  /> </td></tr>

    </form>
    </table>
     <div id = "results2"></div>
</div>

然后 PHP 文件中的代码缩减为初始变量:

/* GRADES VARS */
$grade1 = $_POST['grade1'];
$grade2 = $_POST['grade2'];
$grade3 = $_POST['grade3'];
$grade4 = $_POST['grade4'];
$grade5 = $_POST['grade5'];
$grade6 = $_POST['grade6'];
$grade7 = $_POST['grade7'];
$grade8 = $_POST['grade8'];
$grade9 = $_POST['grade9'];
$grade10 = $_POST['grade10'];
$grade11 = $_POST['grade11'];
$grade12 = $_POST['grade12'];


/* GRADE WEIGHT VARS */
$weight1 = $_POST['weight1'];
$weight2 = $_POST['weight2'];
$weight3 = $_POST['weight3'];
$weight4 = $_POST['weight4'];
$weight5 = $_POST['weight5'];
$weight6 = $_POST['weight6'];
$weight7 = $_POST['weight7'];
$weight8 = $_POST['weight8'];
$weight9 = $_POST['weight9'];
$weight10 = $_POST['weight10'];
$weight11 = $_POST['weight11'];
$weight12 = $_POST['weight12'];

谢谢!

Answer 1

所以基本上你需要使用字段名称作为数组，所以举个例子:

<input type="text" name="someName[]" value="0" />
<input type="text" name="someName[]" value="2" />
<input type="text" name="someName[]" value="4" />
<input type="text" name="someName[]" value="6" />

当您执行 for 提交并将值发布到服务器时，您将能够使用 PHP 以数组形式访问它们，如下所示:

echo $_POST['someName'][0]; // outputs 0
echo $_POST['someName'][1]; // outputs 2
echo $_POST['someName'][2]; // outputs 4
echo $_POST['someName'][3]; // outputs 6

现在，由于您不知道有多少行，因此可以对其进行循环:

foreach($_POST['someName'] as $someName){
    echo $someName; //will output the value 0/2/4/6 depending on the iteration
}

使用 JavaScript 添加按钮时，您只需确保名称相同并带有括号:

$('#addButton').click(function(){
    $('.container').append('<input type="text" name="someName[]" value="someNumber" />');
});

只要你有这个，并且输入位于可以提交的表单标记内，这就可以工作。

编辑，因此根据您添加到初始答案中的代码，我建议利用 PHP 中的数组。

假设您使用了我上面解释的输入(顺便说一下，这可以用于任何可以发布到后端的 HTML 元素 [复选框、输入、文本区域、选择等...])。你可以这样做:

$grades = array();
foreach($_POST['grade'] as $g){
    $grades[] = $g; // add grade from each input to the array
}

// then you can manipulate the data through looping through it.
foreach($grades as $grade){
    // do something here with each grade...whether it be manipulating it
    // or adding it another array with some changes whatever.
}

这应该允许您清理代码，并且您可以对权重执行相同的操作。