谁能帮我解决温度转换器的回声问题 PHP

Question

所以这是我在 PHP

中进行温度转换的代码

<html>
<head> 
      <title>Temp Conversion</title>
      <meta charset="utf-8">
</head>
<body>
    <form name="tempConvert" method="POST" action="<?php echo $_SERVER["PHP_SELF"]; ?>">

        <table>
        <tr>
            <td>Enter value to convert</td>
            <td><input type="text" name="valueConvert" id="valueConvert" size="15"></td>
        </tr>

        <tr>
            <td>Convert from:</td>
            <td><select name="convertFrom" id="convertFrom" size="1">
                       <option disabled> Select a measurement type</option>
                       <option value="celsiusF">Celsius</option>
                       <option value="fahrenheitF">Fahrenheit</option>
                       <option value="kelvinF">Kelvin</option>
                </select>
            </td>
        </tr>
        
        <tr>
            <td>Convert to:</td>
            <td><select name="convertType" id="convertType" size="1">
                       <option disabled> Select a measurement type</option>
                       <option value="celsius">Celsius</option>
                       <option value="fahrenheit">Fahrenheit</option>
                       <option value="kelvin">Kelvin</option>
                </select>
            </td>
        </tr>

        <tr>
            <td><input type="submit" name="btnConvert" id="btnConvert" value="Convert"></td>
            <td><input type="reset" name="btnReset" id="btnReset" value="Reset"></td>
        </tr>



    </form>

    <?php
        function tempConvert($valueConvert, $convertFrom, $convertType)
        {
            if($convertFrom== "celciusF")
            {
                if($convertType== "fahrenheit")
                {
                   $conversion = (((9/5)*$valueConvert) +(32));
                }
                
                else if ($convertType== "celsius")
                {
                   $conversion = ($valueConvert);
                }
                
                else if ($convertType== "kelvin")
                {
                   $conversion = ($valueConvert + 273);
                }
            
            }
            
            else if($convertFrom== "fahrenheitF")
            {
                if($convertType== "fahrenheit")
                {
                   $conversion = ($valueConvert);
                }
                
                else if ($convertType== "celsius")
                {
                   $conversion = (($valueConvert - 32) * (5/9));
                }
                
                else if ($convertType== "kelvin")
                {
                   $conversion = ((($valueConvert - 32) * (5/9)) + 273);
                }
            
            }
            
            else if($convertFrom== "kelvinF")
            {
                if($convertType== "fahrenheit")
                {
                   $conversion = (((9/5)*($valueConvert - 273)) +(32));
                }
                
                else if ($convertType== "celsius")
                {
                   $conversion = ($valueConvert - 273);
                }
                
                else if ($convertType== "kelvin")
                {
                   $conversion = ($valueConvert);
                }
            
            }
            
        
        }

        if (isset($_POST['btnConvert'])) 
        { 
            $valueConvert = $_POST['valueConvert'];
            $convertFrom = $_POST['convertFrom'];
            $convertType = $_POST['convertType'];
            $conversion = tempConvert($valueConvert, $convertFrom, $convertType);
            
            echo "The initial temperature was $valueConvert. The new temperature is $conversion $convertType.";
        }
    ?>

    </body>
</html>

当我运行这个 PHP 代码，然后插入值，然后按下转换按钮。似乎 $conversion 值没有显示在代码最后一部分的回显中。（例如它只会显示为“初始温度为 32。新温度为摄氏度”）

我想知道是什么原因造成的，谁能帮帮我？

Answer 1

好的，感谢 Nigel Ren、ADyson 和 Barmar 的回答，看来我的代码有两个问题，第一个是缺少 return 值，第二个是打字时的错字"celciusF"（应该是celsiusF，用s代替c）

这是正确的代码

<html>
<head> 
      <title>Temp Conversion</title>
      <meta charset="utf-8">
</head>
<body>
    <form name="tempConvert" method="POST" action="<?php echo $_SERVER["PHP_SELF"]; ?>">

        <table>
        <tr>
            <td>Enter value to convert</td>
            <td><input type="text" name="valueConvert" id="valueConvert" size="15"></td>
        </tr>

        <tr>
            <td>Convert from:</td>
            <td><select name="convertFrom" id="convertFrom" size="1">
                       <option disabled> Select a measurement type</option>
                       <option value="celsiusF">Celsius</option>
                       <option value="fahrenheitF">Fahrenheit</option>
                       <option value="kelvinF">Kelvin</option>
                </select>
            </td>
        </tr>
        
        <tr>
            <td>Convert to:</td>
            <td><select name="convertType" id="convertType" size="1">
                       <option disabled> Select a measurement type</option>
                       <option value="celsius">Celsius</option>
                       <option value="fahrenheit">Fahrenheit</option>
                       <option value="kelvin">Kelvin</option>
                </select>
            </td>
        </tr>

        <tr>
            <td><input type="submit" name="btnConvert" id="btnConvert" value="Convert"></td>
            <td><input type="reset" name="btnReset" id="btnReset" value="Reset"></td>
        </tr>



    </form>

    <?php
        function tempConvert($valueConvert, $convertFrom, $convertType)
        {
            if($convertFrom== "celsiusF")
            {
                if($convertType== "fahrenheit")
                {
                   $conversion = (((9/5)*$valueConvert) +(32));
                }
                
                else if ($convertType== "celsius")
                {
                   $conversion = ($valueConvert);
                }
                
                else if ($convertType== "kelvin")
                {
                   $conversion = ($valueConvert + 273);
                }
            
            }
            
            else if($convertFrom== "fahrenheitF")
            {
                if($convertType== "fahrenheit")
                {
                   $conversion = ($valueConvert);
                }
                
                else if ($convertType== "celsius")
                {
                   $conversion = (($valueConvert - 32) * (5/9));
                }
                
                else if ($convertType== "kelvin")
                {
                   $conversion = ((($valueConvert - 32) * (5/9)) + 273);
                }
            
            }
            
            else if($convertFrom== "kelvinF")
            {
                if($convertType== "fahrenheit")
                {
                   $conversion = (((9/5)*($valueConvert - 273)) +(32));
                }
                
                else if ($convertType== "celsius")
                {
                   $conversion = ($valueConvert - 273);
                }
                
                else if ($convertType== "kelvin")
                {
                   $conversion = ($valueConvert);
                }
            
            }
            
        return $conversion;
        }

        if (isset($_POST['btnConvert'])) 
        { 
            $valueConvert = $_POST['valueConvert'];
            $convertFrom = $_POST['convertFrom'];
            $convertType = $_POST['convertType'];
            $conversion = tempConvert($valueConvert, $convertFrom, $convertType);
            
            echo "The initial temperature was $valueConvert. The new temperature is $conversion $convertType.";
        }
    ?>

    </body>
</html>

谁能帮我解决温度转换器的回声问题 PHP

Can someone help me to solve my echo problem for my temperature converter PHP

html

php

forms

echo