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How to implement calculator code in php

藏色散人
藏色散人Original
2020-08-17 09:40:433347browse

php method to implement a calculator: first create a PHP sample file; then use the if statement to determine whether the post has passed the sub parameter; then use the switch statement to determine whether the two operands are numbers; finally create a simple calculation The HTML code of the server is sufficient.

How to implement calculator code in php

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<?php  
    // 判断post是否传过来sub参数,从而判断是提交计算,还是刷新页面  
    if (isset($_POST[&#39;sub&#39;])){  
        echo "用户点击提交按钮,提交计算请求<br>";  
  
// 下面注释掉的代码并不是错误的,只是区别switch的另外一种方式  
//        if ($_POST[&#39;ysf&#39;] == "+"){  
//            echo $_POST[&#39;num1&#39;] + $_POST[&#39;num2&#39;] . "<br>";  
//        }elseif ($_POST[&#39;ysf&#39;] == "-"){  
//            echo $_POST[&#39;num1&#39;] - $_POST[&#39;num2&#39;] . "<br>";  
//        }elseif ($_POST[&#39;ysf&#39;] == "*"){  
//            echo $_POST[&#39;num1&#39;] * $_POST[&#39;num2&#39;] . "<br>";  
//        }elseif ($_POST[&#39;ysf&#39;] == "/"){  
//            echo $_POST[&#39;num1&#39;] / $_POST[&#39;num2&#39;] . "<br>";  
//        }elseif ($_POST[&#39;ysf&#39;] == "%"){  
//            echo $_POST[&#39;num1&#39;] % $_POST[&#39;num2&#39;] . "<br>";  
//        }  
  
        // 判断两个运算元是否为数字 如果不是数字 则不进行运算  
        if (!is_numeric($_POST[&#39;num1&#39;]) || !is_numeric($_POST[&#39;num2&#39;])){  
            $isDo = false;  
            echo "其中一个运算元不是数字,不进行运算<br>";  
        }else{  
            $isDo = true;  
        }  
  
        // 声明变量 计算结果  
        $sum = "";  
  
        if ($isDo){ // 判断两个运算元是否为数字 如果不是数字 则不进行运算  
            switch ($_POST[&#39;ysf&#39;]){  
                case &#39;+&#39;:  
                    $sum = $_POST[&#39;num1&#39;] + $_POST[&#39;num2&#39;];  
                    break;  
                case &#39;-&#39;:  
                    $sum = $_POST[&#39;num1&#39;] - $_POST[&#39;num2&#39;];  
                    break;  
                case &#39;*&#39;:  
                    $sum = $_POST[&#39;num1&#39;] * $_POST[&#39;num2&#39;];  
                    break;  
                case &#39;/&#39;:  
                    $sum = $_POST[&#39;num1&#39;] / $_POST[&#39;num2&#39;];  
                    break;  
                case &#39;%&#39;:  
                    $sum = $_POST[&#39;num1&#39;] % $_POST[&#39;num2&#39;];  
                    break;  
            }  
            echo $sum."<br>";  
        }  
    }else{  
        echo "用户刷新页面<br>";  
        //die("不做计算处理<br>");  
    }  
?>  
  
<html lang="en">  
<head>  
    <meta charset="UTF-8">  
    <title>简易计算器</title>  
</head>  
<body>  
<!--table 表格-->  
<!--border=1,表格周围的边框设置为1像素宽-->  
<!--width=400,表格宽度为400像素宽-->  
<!--align=center,表格水平对齐方式为居中对齐内容-->  
<!--caption 定义表格标题-->  
<!--<h1> 定义最大的标题。<h6> 定义最小的标题。-->  
<!--<tr> 标签定义 HTML 表格中的行。包含一个或多个th或td元素。-->  
<!--ysf 运算符的首字母。-->  
<!--colspan 规定单元格可横跨的列数。-->  
<table border="1" width="400" align="center">  
    <form action="jsq2.php" method="post">  
        <caption><h1>简易计算器</h1></caption>  
        <caption><h4>iwanghang</h4></caption>  
        <tr>  
            <!--第一个运算元-->  
<!--            <td><input type="text" size="5" name="num1" value=""></td>-->  
            <td><input type="text" size="5" name="num1" value="<?php  
                if (isset($_POST[&#39;sub&#39;])){echo $_POST[&#39;num1&#39;];} ?>"></td>  
            <!--运算符-->  
            <td>  
                <select name="ysf">  
<!--                    <option value="+"> + </option>-->  
<!--                    <option value="-"> - </option>-->  
<!--                    <option value="*"> * </option>-->  
<!--                    <option value="/"> / </option>-->  
<!--                    <option value="%"> % </option>-->  
                    <option <?php if (isset($_POST[&#39;sub&#39;])){  
                        if ($_POST[&#39;ysf&#39;]=="+") echo "selected";} ?> value="+"> + </option>  
                    <option <?php if (isset($_POST[&#39;sub&#39;])){  
                        if ($_POST[&#39;ysf&#39;]=="-") echo "selected";} ?> value="-"> - </option>  
                    <option <?php if (isset($_POST[&#39;sub&#39;])){  
                        if ($_POST[&#39;ysf&#39;]=="*") echo "selected";} ?> value="*"> * </option>  
                    <option <?php if (isset($_POST[&#39;sub&#39;])){  
                        if ($_POST[&#39;ysf&#39;]=="/") echo "selected";} ?> value="/"> / </option>  
                    <option <?php if (isset($_POST[&#39;sub&#39;])){  
                        if ($_POST[&#39;ysf&#39;]=="%") echo "selected";} ?> value="%"> % </option>  
                </select>  
            </td>  
            <!--第二个运算元-->  
<!--            <td><input type="text" size="5" name="num2" value=""></td>-->  
            <td><input type="text" size="5" name="num2" value="<?php  
                if (isset($_POST[&#39;sub&#39;])){echo $_POST[&#39;num2&#39;];} ?>"></td>  
            <!--提交-->  
            <td><input type="submit" name="sub" value="等于"></td>  
        </tr>  
        <tr>  
            <td colspan="4">  
                <?php  
                    if (isset($_POST[&#39;sub&#39;])){  
                        echo "计算结果:{$_POST[&#39;num1&#39;]}{$_POST[&#39;ysf&#39;]}{$_POST[&#39;num2&#39;]} = {$sum}";  
                    }  
                ?>  
            </td>  
        </tr>  
    </form>  
</table>  
</body>  
</html>

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