在PHP中设置默认值和记住选择框中的值的问题 - Issue with setting the default value and remembering the values in select box in PHP

Issue with setting the default value and remembering the values in select box in PHP

本文关键字：选择问题 PHP 设置默认值 | 更新日期: 2023-09-27

<form name="search" method="post" >
 Seach for: <input type="text" name="find" value="<?php echo (isset($_POST['find']) ? $_POST['find'] : ''); ?>" /> in
 <Select NAME="field">
 <Option VALUE="category1" <?php echo (isset($_POST['field']) && $_POST['field'] === 'category1') ? 'selected="selected"': ''; ?>>category1</option>
 <Option VALUE="category2" <?php echo (isset($_POST['field']) && $_POST['field'] === 'category2') ? 'selected="selected"': ''; ?>>category2</option>
 </Select>
 <input type="submit" name="search" value="Search" />
 </form>
 <?php
    if(!empty($_POST)){
        $options = array('category1'=> array('1' => 'dog', '2' => 'cat'), 'category2' =>array('1'=>'flower', '2'=>'grass'));
        $input = trim($_POST['find']);
        $category = $_POST['field'];
        $output = $options[$category][$input];
        echo $output;
}
?>

问题:

我怎样才能使category2成为选择框的默认值而不是category1?我试过了:

<Option VALUE="category2" <?php
echo (isset($_POST['field']) && $_POST['field'] === 'category2') ? 'selected="selected"' : '';
?> selected = "selected">category2</option>

但是它破坏了我的函数。输入1，选择category1，点击搜索后，选择框变为category2。那不是我想要的。我希望这个函数像这样执行:

为选择框设置默认值category2。

我怎样才能做到这一点?

try default为cat2, select后为result

  <form method="post"> 
<Select name="field">
 <Option <?php  if(isset($_POST['field']) && $_POST['field'] == "category1")  echo 'selected="selected"'; ?> VALUE="category1" >category1</option>
 <Option <?php if ((isset($_POST['field']) && $_POST['field'] == "category2") OR empty($_POST['field']))  echo 'selected="selected'; ?> VALUE="category2" >category2</option>
 </Select>
 <input type="submit" />
 </form>

你可以这样使用

<form method="post"> 
<Select name="field">
 <Option VALUE="category2" >category2</option>
 <Option <?php  if($_POST['field'] == "category1")  echo 'selected="selected"'; ?> VALUE="category1" >category1</option>
 <Option <?php  if($_POST['field'] == "category3")  echo 'selected="selected"'; ?> VALUE="category3" >category3</option>
 </Select>
 <input type="submit" />
 </form>