Question

我遇到了问题。在这里，我是一个关联数组名称 $ arr 。我通过输入传递了这一点。提交表单后，当我想访问它时，显示 Undefined index：paper （未定义的索引：纸张）。这是我的PHP代码。昨晚我也尝试解决此问题，但不能解决。提前致谢。

<?php
   $arr = array('book' => '20' ,'pen' => '10' ,'paper' => '50' , );

   if($_SERVER["REQUEST_METHOD"] == "POST") {
       $new_arr = $_POST['arr2'];
       echo $new_arr['paper'];
     }
?>

<form action="" method="POST">
    <br><br>
    <input type="hidden" value="<?php echo $arr ?>" name="arr2"><br>
    <input type="submit" name="" value="submit">
</form>

Answer 1

首先将数组作为json

<input type="hidden" value="<?php echo json_encode($arr) ?>" name="arr2"><br>

您需要在$arr中提供密钥，如下所示

<?php
   $arr = array('book' => '20' ,'pen' => '10' ,'paper' => '50');

   if($_SERVER["REQUEST_METHOD"] == "POST") {
       $new_arr = json_decode($_POST['arr2'],true);
       echo $new_arr['paper'];
   }
?>

Answer 2

echo $arr只会产生“ Array”，因此对您没有帮助。但是您可以使用serialize和unserialize：

<?php
   $arr = array('book' => '20' ,'pen' => '10' ,'paper' => '50' , );

   if($_SERVER["REQUEST_METHOD"] == "POST") {
       $new_arr = unserialize($_POST['arr2']);
       echo $new_arr['paper'];
     }
?>

<form action="" method="POST">
    <br><br>
    <input type="hidden" value="<?php echo serialize($arr) ?>" name="arr2"><br>
    <input type="submit" name="" value="submit">
</form>

Answer 3

尝试此代码

将input hidden传递名称用作array key的for循环

<?php
   $arr = array('book' => '20' ,'pen' => '10' ,'paper' => '50' , );

   if($_SERVER["REQUEST_METHOD"] == "POST") {
       $new_arr = $_POST['paper'];
       //print_r($new_arr);
       echo $new_arr;
     }
?>

<form action="" method="POST">
    <br><br>
    <?php foreach($arr as $k=>$v){
       ?>
      <input type="text" value="<?php echo $v ?>" name="<?php echo $k?>"><br>
    <?php
    }
    ?>
    <input type="submit" name="" value="submit">
</form>

Answer 4

简单。首先对数组进行编码，以文本形式存储在单个元素内，然后对相同的值进行解码。

<?php
   $arr = json_encode(array('book' => '20' , 'pen' => '10' , 'paper' => '50'));
   if($_SERVER["REQUEST_METHOD"] == "POST") {
       $new_arr = json_decode($_POST['arr2'], TRUE);
       echo $new_arr['book'];
       echo $new_arr['pen'];
       echo $new_arr['paper'];
   }
?>

<form action="" method="POST">
    <input type="hidden" value='<?php echo $arr; ?>' name="arr2"><br>
    <input type="submit" name="" value="submit">
</form>

在PHP中关联数组的传递和访问

4 个答案: