PHP教程 4.2.9 PHP实例(简单计算器)4

jsq.php

<?php
    error_reporting(E_ALL & ~E_NOTICE);

    if( isset($_POST['sub']) ) {
        //echo "用户是提交了";
        
        $bz = true; 

        $errormess = "有以上问题:<br>";
        
        if($_POST['num1'] == "") {
            $bz = false;
            $errormess .= "第一个数不能为空<br>";

        } else {
            if(!is_numeric($_POST['num1'])) {
                $bz = false;
                $errormess .="第一个不是数字不能计算<br>"; 
            }
        }

        if($_POST['num2'] == "") {
            $bz = false;
            $errormess .= "第二个数不能为空<br>";
        }else {
            if(!is_numeric($_POST['num2'])) {
                $bz = false;
                $errormess .="第二个不是数字不能计算<br>"; 
            }

        }





    



        if($bz) {

            //这个是计算后的结果
            $sum = "";
        
            //判断用户选择的是那个运算符号
            switch($_POST['ysf']) {
                case '+': 
                    $sum = $_POST['num1'] + $_POST['num2']; 
                    break;
                case '-': 
                    $sum = $_POST['num1'] - $_POST['num2']; 
                    break;
                case 'x': 
                    $sum = $_POST['num1'] * $_POST['num2']; 
                    break;
                case '/': 
                    $sum = $_POST['num1'] / $_POST['num2']; 
                    break;
                case '%': 
                    $sum = $_POST['num1'] % $_POST['num2']; 
                    break;
        
            
            }
        }
    

    } 

echo '<br>';
?>

<html>
    <head>
        <title>简单计算器</title>
    </head>

    <body>
        <table border="0" width="400" align="center">
        <form action="jsq.php" method="post">
            <caption><h1>简单计算器</h1></caption>

            <tr>
                <td> 
                    <input type="text" size="5" name="num1" value="<?php echo $_POST['num1'] ?>" /> <br>
                </td>

                <td>
                    <select name="ysf">
                        <option <?php if($_POST['ysf']=="+") echo "selected" ?> value="+"> + </option>
                        <option <?php if($_POST['ysf']=="-") echo "selected" ?>  value="-"> - </option>
                        <option <?php echo $_POST['ysf']=="x" ? "selected" : "" ?>  value="x"> x </option>
                        <option <?php if($_POST['ysf']=="/") echo "selected" ?>  value="/"> / </option>
                        <option <?php if($_POST['ysf']=="%") echo "selected" ?>  value="%"> % </option>
                    </select>
                </td>

                <td>

                    <input type="text" size="5" name="num2" value="<?php echo $_POST['num2'] ?>" /> <br>
                </td>


                <td>
                    <input type="submit" name="sub" value="计算">
                </td>
            <tr>

            <tr>
                <td colspan="4">

                    <?php
                        if($bz) {

                            echo "计算结果: {$_POST['num1']} {$_POST['ysf']} {$_POST['num2']} = {$sum}";
                        } else {
                        
                            echo $errormess;
                        }

                    ?>
                </td>
            </tr>
        </form>
        </table>
    </body>
</html>
    原文作者:caoyuan
    原文地址: https://www.jianshu.com/p/52c0c0077cba
    本文转自网络文章,转载此文章仅为分享知识,如有侵权,请联系博主进行删除。
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