$ _POST未定义索引PHP错误 [英] $_POST undefined index PHP error
问题描述
接收字符串的我的html代码：
<！DOCTYPE html>
< head>
< title> title< / title>
< / head>
< body>
< font face =Segoe UIsiz =3>
< form action =process.phpaction =post>
建议：< input type =textname =sgstautocomplete =off>
< input type =submit>
< / form>
< / font>
< / body>
< / html>
我的PHP处理它：（process.php）
<？php
if（$ _POST [sgst] ==john）{
echojohn;
} else {
echosomeone;
}
？>
我收到错误
注意：未定义的索引：第2行的C：\ xampp \\\ htdocs \ test \ process.php中的sgst
谁能告诉我导致错误的原因是什么？
你正在重复使用<$ c 表单中的$ c> action 属性：
< form action =process.phpaction =post>
我很惊讶表单甚至在发布时都是这样。尽管有这些症状，但似乎至少足以混淆POST。我想你应该使用方法属性：
< form action =process.phpmethod =post>
其他注意事项：
- 您需要在服务器端代码中使用
isset（）。该代码不应该假设所有值都将被公布，因为服务器无法控制客户端发送的内容。最好在使用它之前明确验证数据。 -
font元素是相当过时的，如果它们没有正式弃用他们应该是:) CSS样式将成为客户端UI风格的方式。
My html code which receives the string:
<!DOCTYPE html>
<head>
<title>title</title>
</head>
<body>
<font face="Segoe UI" siz ="3">
<form action="process.php" action="post">
Suggestion: <input type="text" name="sgst" autocomplete="off">
<input type="submit">
</form>
</font>
</body>
</html>
My PHP which processes it: (process.php)
<?php
if ($_POST["sgst"]=="john") {
echo "john";
} else {
echo "someone";
}
?>
I am getting the error
Notice: Undefined index: sgst in C:\xampp\htdocs\test\process.php on line 2
Can anyone tell me what is causing the error?
You're re-using the action attribute on the form element:
<form action="process.php" action="post">
I'm surprised the form is even posting at all given that. Though given the symptoms it seems to at least be enough to confuse the POST. I think you meant to use the method attribute:
<form action="process.php" method="post">
A couple other notes:
- You'll want to make use of
isset()in your server-side code. The code shouldn't assume that all values will be posted, since the server can't control what a client sends it. Best to explicitly validate the data coming in before using it. fontelements are pretty dated, and if they're not officially deprecated they should be :) CSS styling would be the way to go for client-side UI styles.
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