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>
