我的php代码赢得'；你不能用HTML运行吗？_Php_Html

我的php代码赢得'；你不能用HTML运行吗？

php html

我的php代码赢得'；你不能用HTML运行吗？,php,html,Php,Html,我正在一个简单的web表单问题上练习php。长话短说，我只需要创建一个非常基本的web表单，它包含欧洲城市的二维数组，以公里为单位显示它与其他欧洲城市的距离。我所需要做的就是创建一个web表单，在该表单中，您可以输入在二维数组中找到的任何城市，并让它计算起点城市和终点城市之间的距离（即，在文本字段中输入“Berlin”和“Prague”后，Berlin位于离布拉格不远的地方）我想我的问题几乎解决了，但问题是phpstorm告诉我某些变量是未定义的，即使它们已经在我的函数中定义了，并且在该函数之

我正在一个简单的web表单问题上练习php。长话短说，我只需要创建一个非常基本的web表单，它包含欧洲城市的二维数组，以公里为单位显示它与其他欧洲城市的距离。我所需要做的就是创建一个web表单，在该表单中，您可以输入在二维数组中找到的任何城市，并让它计算起点城市和终点城市之间的距离（即，在文本字段中输入“Berlin”和“Prague”后，Berlin位于离布拉格不远的地方）

我想我的问题几乎解决了，但问题是phpstorm告诉我某些变量是未定义的，即使它们已经在我的函数中定义了，并且在该函数之前是一个变量。如果这个问题看起来微不足道，我很抱歉，但我现在正在学习理解php。下面是我的代码。我包括了html和php代码放在一个页面中

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Distance between European Cities</title>
</head>
<body>
<h1>Distance between European Cities</h1>
<h2>Enter valid European cities from this list: Berlin, Moscow, Paris, Prague, Rome</h2>
<?php
$Distances = array(
    "Berlin" => array("Berlin" => 0, "Moscow" => 1607.99, "Paris" => 876.96, "Prague" => 280.34, "Rome" => 1181.67),
    "Moscow" => array("Berlin" => 1607.99, "Moscow" => 0, "Paris" => 2484.92, "Prague" => 1664.04, "Rome" => 2374.26),
    "Paris" => array("Berlin" => 876.96, "Moscow" => 641.34, "Paris" => 0, "Prague" => 885.38, "Rome" => 1105.76),
    "Prague" => array("Berlin" => 280.34, "Moscow" => 1607.99, "Paris" => 885.38, "Prague" => 0, "Rome" => 922),
    "Rome" => array("Berlin" => 1181.67, "Moscow" => 2374.26, "Paris" => 1105.76, "Prague" => 922, "Rome" => 0));
$KMtoMiles = 0.62;
$City1 = $_POST['firstCity'];
$City2 = $_POST['secondCity'];
function euDis($City1, $City2, $Distances){
if (empty($City1) || empty($City2)) {
    echo "Please input two cities in the required fields.<br />\n";
} elseif (in_array($City1, $Distances) == FALSE || in_array($City2, $Distances) == FALSE) {
    echo "You inputted one or more cities that are not in our list.<br />";
} else {
    if (isset($_POST['submit'])) {
        $City1 = stripslashes($_POST['firstCity']);
        $City2 = stripslashes($_POST['secondCity']);
        if (isset($Distances[$City1][$City2])) {
            echo "<p>The distance from $City1 to $City2 is " . $Distances[$City1][$City2] . " kilometers or " . round((0.62 * $Distances[$City1][$City2]), 2) . " miles.</p>\n";
        } else {
            echo "<p>$City1 and $City2 are not in this list.</p>\n";
        }
    }
}
}
?>
<form action= "eudistance.php" method="post">

City 1: <input type="text" name="firstCity" /><br />

City 2: <input type="text" name="secondCity" /><br />

<input type="reset" value="Clear All" />

<input type="submit" name="submit" value="Enter" />

</form>
</body>
</html>


欧洲城市之间的距离
欧洲城市之间的距离
在此列表中输入有效的欧洲城市：柏林、莫斯科、巴黎、布拉格、罗马
城市1:

城市2:

您的php代码首先执行，因此会出现一些错误。只需添加

if(isset($_POST['submit'])){
...
}

在php代码中，这样php代码只有在提交表单详细信息后才会执行

$City1 = $_POST['firstCity'];
$City2 = $_POST['secondCity'];

以上两个变量没有初始化，它们是从表单中获取值，因此在执行php代码之前需要提交表单数据。您应该调用函数来计算距离

函数调用：

if(isset($_POST['submit']))
{
$KMtoMiles = 0.62;
$City1 = $_POST['firstCity'];
$City2 = $_POST['secondCity'];
euDis(trim($City1),trim($City2));  //function calling
}

像这样：

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Distance between European Cities</title>
</head>
<body>
<h1>Distance between European Cities</h1>
<h2>Enter valid European cities from this list: Berlin, Moscow, Paris, Prague, Rome</h2>
<?php
if(isset($_POST['submit']))
{
$KMtoMiles = 0.62;
$City1 = $_POST['firstCity'];
$City2 = $_POST['secondCity'];
euDis(trim($City1),trim($City2));
}
function euDis($City1, $City2){
$Distances = array(
    "Berlin" => array("Berlin" => 0, "Moscow" => 1607.99, "Paris" => 876.96, "Prague" => 280.34, "Rome" => 1181.67),
    "Moscow" => array("Berlin" => 1607.99, "Moscow" => 0, "Paris" => 2484.92, "Prague" => 1664.04, "Rome" => 2374.26),
    "Paris" => array("Berlin" => 876.96, "Moscow" => 641.34, "Paris" => 0, "Prague" => 885.38, "Rome" => 1105.76),
    "Prague" => array("Berlin" => 280.34, "Moscow" => 1607.99, "Paris" => 885.38, "Prague" => 0, "Rome" => 922),
    "Rome" => array("Berlin" => 1181.67, "Moscow" => 2374.26, "Paris" => 1105.76, "Prague" => 922, "Rome" => 0));


if (empty(trim($City1)) || empty(trim($City2)))  {
    echo "Please input two cities in the required fields.<br />\n";
} 
 else {
        if (isset($Distances[$City1][$City2])) {
            echo "<p>The distance from $City1 to $City2 is " . $Distances[$City1][$City2] . " kilometers or " . round((0.62 * $Distances[$City1][$City2]), 2) . " miles.</p>\n";} 
        else {
            echo "<p>$City1 and $City2 are not in this list.</p>\n";
        }    }
}
?>

<form action= "" method="post">

City 1: <input type="text" name="firstCity" /><br />

City 2: <input type="text" name="secondCity" /><br />

<input type="reset" value="Clear All" />

<input type="submit" name="submit" value="Enter" />

</form>
</body>
</html>


欧洲城市之间的距离
欧洲城市之间的距离
在此列表中输入有效的欧洲城市：柏林、莫斯科、巴黎、布拉格、罗马
城市1:

城市2:

我改变了以下事情

你没有调用你的函数

城市名称是数组的

key

。\u数组中的

返回true
如果变量是数组的成员，而不是key



欧洲城市之间的距离
欧洲城市之间的距离
在此列表中输入有效的欧洲城市：柏林、莫斯科、巴黎、布拉格、罗马
城市1:

城市2:

代码中有两个问题。第一个问题是在分配post变量之前检查数据是否可用。第二个问题是距离数组中可用的城市
已修复您的问题。请尝试此代码一次
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Distance between European Cities</title>
</head>
<body>
<h1>Distance between European Cities</h1>
<h2>Enter valid European cities from this list: Berlin, Moscow, Paris, Prague, Rome</h2>
<?php
$Distances = array(
    "Berlin" => array("Berlin" => 0, "Moscow" => 1607.99, "Paris" => 876.96, "Prague" => 280.34, "Rome" => 1181.67),
    "Moscow" => array("Berlin" => 1607.99, "Moscow" => 0, "Paris" => 2484.92, "Prague" => 1664.04, "Rome" => 2374.26),
    "Paris" => array("Berlin" => 876.96, "Moscow" => 641.34, "Paris" => 0, "Prague" => 885.38, "Rome" => 1105.76),
    "Prague" => array("Berlin" => 280.34, "Moscow" => 1607.99, "Paris" => 885.38, "Prague" => 0, "Rome" => 922),
    "Rome" => array("Berlin" => 1181.67, "Moscow" => 2374.26, "Paris" => 1105.76, "Prague" => 922, "Rome" => 0));
$KMtoMiles = 0.62;
if(isset($_POST['submit'])){
    $City1 = $_POST['firstCity'];
    $City2 = $_POST['secondCity'];

    if (empty($City1) || empty($City2)) {
        echo "Please input two cities in the required fields.<br />\n";
    } elseif (is_array($Distances[$City1]) == False || is_array($Distances[$City2])== false ) {
        echo "You inputted one or more cities that are not in our list.<br />";
    } else {
        if (isset($_POST['submit'])) {
            $City1 = stripslashes($_POST['firstCity']);
            $City2 = stripslashes($_POST['secondCity']);
            if (isset($Distances[$City1][$City2])) {
                echo "<p>The distance from $City1 to $City2 is " . $Distances[$City1][$City2] . " kilometers or " . round((0.62 * $Distances[$City1][$City2]), 2) . " miles.</p>\n";
            } else {
                echo "<p>$City1 and $City2 are not in this list.</p>\n";
            }
        }
    }

}
?>
<form action= "" method="post">

City 1: <input type="text" name="firstCity" /><br />

City 2: <input type="text" name="secondCity" /><br />

<input type="reset" value="Clear All" />

<input type="submit" name="submit" value="Enter" />

</form>
</body>
</html>


欧洲城市之间的距离
欧洲城市之间的距离
在此列表中输入有效的欧洲城市：柏林、莫斯科、巴黎、布拉格、罗马
城市1:

城市2:

实际发生了什么？是否有错误？当我在浏览器上运行它时，会出现502错误。当我在phpstorm上运行它时，它会告诉我“PHP通知：未定义索引：C:\Users\user\PhpstormProjects\eudistance.PHP第19行中的firstCity PHP通知：未定义索引：C:\Users\user\PhpstormProjects\eudistance.PHP第20行中的secondCity”我认为我的参数是通过前两个变量定义的，这两个变量从输入的文本字段中检索文本。PHP代码不会做任何事情。它只是定义和设置变量$distance
，$KMtoMiles
，$City1
和$City2
，以及一个函数euDis
，其他什么都没有n不会在任何地方调用。此外，当第一次执行时（不向其发送表单数据），您将读取未定义的索引$\u POST['firstCity']
和$\u POST['secondCity']
因为$\u POST数组是空的。html代码必须在php代码之前插入吗？或者我只是误解了这些变量是如何工作的？你修复了未定义的索引问题，但这段代码仍然没有做任何事情。是的，它可以工作。如果我想，我可以使用一些elseif语句对其进行压缩，对吗？是的，你可以使用elseif语句。谢谢。这也很有效，看起来也很整洁。我应该养成将php和html代码分开的习惯。是的，如果你这样做，你可以很容易地理解错误。在html中添加php代码应该只是为了显示一些值，所以你的代码会变得更干净。如果我能帮助你，我很高兴。
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Distance between European Cities</title>
</head>
<body>
<h1>Distance between European Cities</h1>
<h2>Enter valid European cities from this list: Berlin, Moscow, Paris, Prague, Rome</h2>
<?php
$Distances = array(
    "Berlin" => array("Berlin" => 0, "Moscow" => 1607.99, "Paris" => 876.96, "Prague" => 280.34, "Rome" => 1181.67),
    "Moscow" => array("Berlin" => 1607.99, "Moscow" => 0, "Paris" => 2484.92, "Prague" => 1664.04, "Rome" => 2374.26),
    "Paris" => array("Berlin" => 876.96, "Moscow" => 641.34, "Paris" => 0, "Prague" => 885.38, "Rome" => 1105.76),
    "Prague" => array("Berlin" => 280.34, "Moscow" => 1607.99, "Paris" => 885.38, "Prague" => 0, "Rome" => 922),
    "Rome" => array("Berlin" => 1181.67, "Moscow" => 2374.26, "Paris" => 1105.76, "Prague" => 922, "Rome" => 0));
$KMtoMiles = 0.62;
if(isset($_POST['submit'])){
    $City1 = $_POST['firstCity'];
    $City2 = $_POST['secondCity'];

    if (empty($City1) || empty($City2)) {
        echo "Please input two cities in the required fields.<br />\n";
    } elseif (is_array($Distances[$City1]) == False || is_array($Distances[$City2])== false ) {
        echo "You inputted one or more cities that are not in our list.<br />";
    } else {
        if (isset($_POST['submit'])) {
            $City1 = stripslashes($_POST['firstCity']);
            $City2 = stripslashes($_POST['secondCity']);
            if (isset($Distances[$City1][$City2])) {
                echo "<p>The distance from $City1 to $City2 is " . $Distances[$City1][$City2] . " kilometers or " . round((0.62 * $Distances[$City1][$City2]), 2) . " miles.</p>\n";
            } else {
                echo "<p>$City1 and $City2 are not in this list.</p>\n";
            }
        }
    }

}
?>
<form action= "" method="post">

City 1: <input type="text" name="firstCity" /><br />

City 2: <input type="text" name="secondCity" /><br />

<input type="reset" value="Clear All" />

<input type="submit" name="submit" value="Enter" />

</form>
</body>
</html>