我用php做了一个页面，通过输入分数来查找分数(LOL)分别是index.php和php.php当我在索引页输入标记时，一切都很好
但是当我直接跳转到php.php，失败的消息来了，IDK为什么。
我想修复它。
index . php
<html>
<head>
<title>Know your grade</title>
<style type="text/css">
input[type=number]::-webkit-outer-spin-button,
input[type=number]::-webkit-inner-spin-button {
-webkit-appearance: none;
margin: 0;
}
input[type=number] {
-moz-appearance:textfield;
}
body{
height: auto;
max-width: 100%;
}
#abt{
opacity: 0.3;
-webkit-transition: opacity 2s;
transition-timing-function: ease;
text-shadow: 0.5px 0.5px blue;
}
#abt:hover{
opacity: 1;
}
#wn{
text-decoration: none;
color: black;
text-shadow: 0.5px 0.5px navy blue;
-webkit-transition: color 0.5s;
}
#wn:hover{
color:red;
}
#reset{
-webkit-transition: color 1s , background-color 1.5s;
}
#reset:hover{
color:blue;
background-color: yellow;
}
</style>
</head>
<body>
<h1 style="text-align:center;font-family:MS comic Sans">Whats your grade?</h1>
<div style="text-align:center;font-family:Georgia;">
<form type="text" method="post" action="php.php">
Enter Marks : <input id="marks" name="marks" min="0" step="0.5" type="number" placeholder=" marks " required="required" oninput="validity.valid||(value='')">
<input type="submit" value="Submit"><br><br>
<input type="reset" name="Reset" id="reset">
</form>
</div>
<br>
<br>
<br>
<p style="text-align:center">How to use this : Enter marks of a subject , Press Enter or Click submit and know your grade.</p>
<p style="text-align:center"><b>Note:</b> Maximum marks is 100 </p>
<div id="abt" style="bottom:0px;position:fixed;right:0px;margin-right:10px;margin-bottom:5px">
<span style="margin:0 auto;display:table;"><u>About</u></span><br>
Developer : <u>Srijan Mukhrjee</u><br>
Proposed on : <u>26-09-2016</u><br>
Completed on : <u>26-09-2016</u><br>
Version : <u>2.<span style="font-size: 10px">1</span></u> (Latest version)<br>
<span style="display: table;margin: 0 auto"><a href="Whatsnew.html" id="wn">(What's New)</a></span>
</div>
</body>
</html>
Php.php
<?php
error_reporting(E_ALL ^ E_NOTICE);
$Mymarks = $_POST['marks'];
$fail = "<h3>We are sorry to say that you failed with poor marks - work hard</h3>"."<h4>Improve yourself and try better next time</h4>"."<h4>Your marks is "."<span style='color:red'>".$Mymarks."</span>"." </h5>";
if($Mymarks >=92 && $Mymarks <=100){
echo "You have got A1 "."Your marks is ".$Mymarks;
}
elseif($Mymarks >=84 && $Mymarks <=91){
echo "You have got A2 "."<br>"."And your marks is ".$Mymarks ;
}
elseif($Mymarks >=76 && $Mymarks <=83){
echo "You have got B1 "."<br>"."And your marks is ".$Mymarks;
}
elseif($Mymarks >=68 && $Mymarks <=75){
echo "You have got B2 "."<br>"."And your marks is ".$Mymarks;
}
elseif($Mymarks >=60 && $Mymarks <=67){
echo "You have got C1 "."<br>Try better next time<br>"."And your marks is ".$Mymarks;
}
elseif($Mymarks >=52 && $Mymarks <=59){
echo "You have got C2 "."<br>Improve yourself<br>"."And your marks is ".$Mymarks;
}
elseif($Mymarks >=44 && $Mymarks <=58){
echo "You have got D1 "."<br>Improve yourself<br>"."And your marks is ".$Mymarks;
}
elseif($Mymarks >=36 && $Mymarks <=57){
echo "You have got E1 "."<br>Improve yourself<br>"."And your marks is ".$Mymarks;
}
elseif($Mymarks < 36){
echo $fail;
}
elseif($Mymarks > 100){
echo "You Entered Marks greater than 100";
}
?>
当我直接打开php而不经过index.php时，观察到失败消息
我该如何修复它?
当您直接访问PHP时，它不会收到您期望的POST值。您应该包含首先验证$_POST['marks']设置的逻辑，如果没有，则适当处理。
if(isset($_POST['marks'])){
//Handle
}
else{
//Default
}
您必须检查从表单中发布的值是否存在，然后根据它创建条件。
这样做的函数叫做isset()。
isset -确定一个变量是否被设置并且不是NULL
描述:
判断一个变量是否被设置并且不为NULL
如果一个变量已经被unset()取消设置，它将不再被设置。如果测试的变量被设置为NULL, isset()将返回FALSE。还要注意，空字符("'0")不等同于PHP的null常量。
如果提供了多个参数，那么isset()只会在设置了所有参数的情况下返回TRUE。从左到右计算，一旦遇到未设置的变量就停止。
Returns TRUE if var exists and has value other than NULL, FALSE otherwise.
根据您的示例，您需要执行以下操作。
if(isset($_POST['marks']))
$marks= $_POST['marks'];
else
die("Mark not provided. Please Ensure you provide it.");