问题：设置默认值并记住PHP中选择框中的值 [英] Issue with setting the default value and remembering the values in select box in PHP

问题描述

 < form name =searchmethod =post> 
搜寻：< input type =textname =findvalue =<？php echo（isset（$ _ POST ['find']）？$ _POST ['find']：'' ）;？> /> in 
< Select NAME =field> 
< Option VALUE =category1<？php echo（isset（$ _ POST ['field']）&& $ _POST ['field'] ==='category1'）？ 'selected =selected'：''; ？>>类别1< /选项> 
< Option VALUE =category2<？php echo（isset（$ _ POST ['field']）&& $ _POST ['field'] ==='category2'）？ 'selected =selected'：''; ？>>类别2< /选项> 
< /选择> 
< input type =submitname =searchvalue =Search/> 
< / form> 
 <？php 
 if（！empty（$ _ POST））{
 $ options = array（'category1'=> array（'1'=>'dog'，' 2'=>'cat'），'category2'=>数组（'1'=>'flower'，'2'=>'grass'））; 
 $ input = trim（$ _ POST ['find']）; 
 $ category = $ _POST ['field']; 
 $ output = $ options [$ category] ​​[$ input]; 
 echo $ output; 
} 
？> 
  

问题：

我该如何制作category2是选择框而不是category1的默认值？我试过这个：

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

但它破坏了我的功能。当我输入 1 并选择 category1 时，点击搜索后，选择框变为类别2 。这不是我想要的。我希望这个功能能够像这样执行：

1. 记住用户为输入字段和选择框所设置的值。 $ b
2. 为选择框设置默认值 category2 。

我怎么能做到这一点？

解决方案

试试默认会是cat2，选择后会得到结果

 < 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）或者空（$ _ POST ['field' ]））echo'selected =selected;？> VALUE =category2> category2< / option> 
< / Select> 
< input type =submit/> 
< / form> 
  

<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;
}
?>

Question:

How could I make category2 to be the default value for the select box instead of category1? I tried this:

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

but it breaks my function. When I input 1 and select category1, after I clicked search, the select box changed to category2. That is not what I want. I want this function to perform like this:

1. Remember the values that user make for input field and select box.
2. Set the default value category2 for the select box.

How could I achieve this?

解决方案

try default will be cat2 and after selected will be 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>

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