PHP AND IF statement

本文关键字：statement IF AND PHP | 更新日期: 2023-11-12

im字符串从一个简单的html页面调用php页面，我找不到语法错误这是html

<html>
<body style="background-color:#990000;">
<h5 align="center" style="font-family:tahoma;color:white;font-size:50px;"> Welcome! </h5> 
<form align="center" method="post" action="php_site.php"> 
First name: <input type="text" name="firstname"><br>
Last name: <input type="text" name="lastname"><br>
<input type="submit" value="Search!">
</form>
</body>
</html>

这是php

<?php   
if (isset($_POST['firstname']) && (isset($_POST['lastname'])))
{
    echo "Welcome $_POST['firstname']";
    echo "This is your last name $_POST['lastname']";  
}
else 
{
    echo "This is Empty!";
}
?>

谢谢！

字符串中嵌入的$_POST引用的语法不太正确。修复它的一些方法是：

用{}括号括起来：

echo "Welcome {$_POST['firstname']}";
echo "This is your last name {$_POST['lastname']}";

或者，删除单引号：

echo "Welcome $_POST[firstname]";
echo "This is your last name $_POST[lastname]";

或者，使用字符串连接.而不是嵌入：

echo "Welcome " . $_POST['firstname'];
echo "This is your last name " . $_POST['lastname'];

和/或，先将值拉入明文命名的变量中：

$firstname = $_POST['firstname'];
$lastname = $_POST['lastname'];
echo "Welcome $firstname";
echo "This is your last name $lastname";

请参阅有关字符串中的变量解析的文档。

试试这个：

<?php   
if (isset($_POST['firstname']) && isset($_POST['lastname']))
{
    echo "Welcome ".$_POST['firstname'];
    echo "This is your last name ".$_POST['lastname'];  
}
else 
{
    echo "This is Empty!";
}
?>

<?php   
    if (isset($_POST['firstname']) && isset($_POST['lastname']) )
    {
        echo "Welcome ".$_POST['firstname'];
        echo "This is your last name $_POST['lastname']";  
    }
    else 
    {
        echo "This is Empty!";
    }
?>

首先，您应该将$_POST值设置为变量。

    $firstname = $_POST['firstname'];
    $lastname = $_POST['lastname'];

然后，确保使用连接标点.:从变量中分离字符串

echo "Welcome" . $firstname;代替echo "Welcome $_POST['firstname']";

此外，请发布您收到的语法错误。如果PHP正在崩溃（死亡的白色屏幕），那么请添加ini_set("display_errors", "1");以便将错误写入屏幕，然后发布错误输出。