我无法在 php 中获取选择框的多个选定值

Question

因此，我有一个 HTML/PHP 表单，它有一个选择列表框，您可以从中选择多个值，因为它的多个属性设置为多个。考虑表单方法是“POST”。但是当我点击 SUBMIT 时，列表框只保存了一个值（具体来说是最后选择的值）。我不知道为什么。

这是我的代码的一部分：

    <?php

    if(isset($_POST['submitSave'])) {

    // Disable errors due to empty xml files

        error_reporting(E_ALL & ~E_WARNING);

        $domDoc = new DOMDocument('1.0', 'UTF-8');

        $domDoc->preserveWhiteSpace = false;

        $domDoc->formatOutput = true;

        $domDoc->encoding = 'UTF-8';

        $domDoc->load('./data/expression.xml');

        $xpath = new DOMXpath($domDoc);

        if($domDoc->getElementsByTagName('expression')->length>0){

            // If we already have expression tag defined

            $expression = $domDoc->getElementsByTagName('expression')[0];

        }else{

            // If we don't have any expression tag, i.e. file is empty

            $expression = $domDoc->createElement('expression');

        }

    $vocabulario = $domDoc->createElement('vocabulario');

    $vocabulario->setAttribute('word', $_POST['word']);

    $classe = $domDoc->createElement('classe', $_POST['classe']);

    $domDoc->appendChild($expression);

    $expression->appendChild($vocabulario);

    $vocabulario->appendChild($classe);

    file_put_contents('./data/expression.xml', $domDoc->saveXML());

    header('location:index.php');

}

?>

<form method="post">

<div class="col-75">

  <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

  <script src="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.3/js/select2.min.js"></script>

  <link href="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.3/css/select2.css" rel="stylesheet" />

  <select name="classe[]" multiple="multiple">

    <option value="| adjective |">adjective</option>

    <option value="| adverb |">adverb</option>

    <option value="| noun |">noun</option>

    <option value="| verb |">verb</option>

  </select>

  <script type="text/javascript">

    var s2 = $("#classe").select2({

      placeholder: "Select",

      tags: true

    });

  </script>

</div>

Answer 1

该代码适合我：/home/vagrant/foo/index.php:3:array (size=2)  'classe' =>     array (size=2)      0 => string '| adjective |' (length=13)      1 => string '| adverb |' (length=10)  'submitSave' => string 'Save' (length=4)在 PHP 中有一些特殊的配置？我的测试：<?phpvar_dump($_POST);?><form method="POST">     <div class="col-75">    <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script><script src="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.3/js/select2.min.js"></script><link href="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.3/css/select2.css" rel="stylesheet"/>    <select id="classe" name="classe[]" multiple name="event_type[]" class="form-control" required>  <option value="| adjective |">adjective</option>  <option value="| adverb |">adverb</option>  <option value="| noun |">noun</option>  <option value="| verb |">verb</option></select><script type="text/javascript">        var s2 = $("#classe").select2({    placeholder: "Select",    tags: true});    </script></div><div class="row">            <td><input type="submit" value="Save" name="submitSave"></td>    </div>  </form>编辑：当你在 PHP 中接收数组数据时，在你的情况下：<select name="classes[]" >PHP var$_POST['classes']不是$_POST['classes[]']，它是一个数组，如果你想将它用作字符串，你必须使用implode