提问人：user2732815 提问时间：8/31/2013 更新时间：8/31/2013 访问量：234
用 $_POST 索引未定义的 PHP
index undefined php with $_POST
问：
我正在尝试摆脱未定义的索引。每次单击提交而不勾选该框时，我都会收到未定义的索引错误。
<html>
<head>
<title>Order</Title>
<style>
</style>
<body>
<form action = "order.php" method = "post">
Coffee:<p>
<input type = "checkbox" value = "coffee" name = "cappuccino"/>Capuccino<br>
</form>
</body>
</head>
</Html>
<?php
$capuccino = 3.75;
if(isset($_POST["submit"]))
{
if($_POST['cappuccino'] <> 'coffee')
{
$capuccino = 0;
}
}
?>
答：
1赞
GautamD31
8/31/2013
#1
尝试点赞isset
<?php
if(isset($_POST["submit"]))
{
if(isset($_POST['cappuccino']) && $_POST['cappuccino'] <> 'coffee')
{
$capuccino = 0;
}
}
?>
您也可以改用!=<>
$_POST['cappuccino'] != 'coffee'
评论
0赞
GautamD31
8/31/2013
告诉我是谁打倒这个的原因
1赞
Paul
8/31/2013
#2
在 HTML 表单中，如果不检查值，则不会发布该值。你应该测试它是否是先发布的，所以你的 php 代码将是这样的：
<?php
if(isset($_POST["submit"]))
{
if(isset($_POST['cappuccino']) && $_POST['cappuccino'] <> 'coffee')
{
$capuccino = 0;
}
}
?>
0赞
Sankalp Mishra
8/31/2013
#3
您的条件应该是：
if(array_key_exists('cappuccino', $_POST) && isset($_POST['cappuccino']) && $_POST['cappuccino'] <> 'coffee')
0赞
user2727841
8/31/2013
#4
<html>
<head>
<title>Order</Title>
<style>
</style>
<body>
<form action = "order.php" method = "post">
Coffee:<p>
<input type = "checkbox" value = "coffee" name = "cappuccino"/>Capuccino<br>
<input type="submit" name="submit" value="Submit" />
</form>
</body>
</head>
</Html>
<?php
$capuccino = 3.75;
if(isset($_POST["submit"]))
{
if(isset($_POST['cappuccino']) && !empty($_POST['cappuccino']) <> 'coffee')
{
$capuccino = 0;
}
}
?>
评论
isset