php实现计算器代码
以下是一个简单的PHP计算器实现代码示例，支持加减乘除运算：
基础实现代码
<?php
$result = 0;
if ($_SERVER["REQUEST_METHOD"] == "POST") {
$num1 = $_POST['num1'];
$num2 = $_POST['num2'];
$operation = $_POST['operation'];
switch ($operation) {
case 'add':
$result = $num1 + $num2;
break;
case 'subtract':
$result = $num1 - $num2;
break;
case 'multiply':
$result = $num1 * $num2;
break;
case 'divide':
$result = ($num2 != 0) ? ($num1 / $num2) : "除数不能为零";
break;
}
}
?>
<!DOCTYPE html>
<html>
<head>
<title>PHP计算器</title>
</head>
<body>
<form method="post">
<input type="number" name="num1" required>
<select name="operation">
<option value="add">+</option>
<option value="subtract">-</option>
<option value="multiply">×</option>
<option value="divide">÷</option>
</select>
<input type="number" name="num2" required>
<button type="submit">计算</button>
</form>
<p>结果: <?php echo $result; ?></p>
</body>
</html>增强版实现（包含验证）
<?php
$errors = [];
$result = '';
if ($_SERVER["REQUEST_METHOD"] == "POST") {
if (empty($_POST['num1']) || empty($_POST['num2'])) {
$errors[] = "两个数字都必须填写";
} else {
$num1 = floatval($_POST['num1']);
$num2 = floatval($_POST['num2']);
$operation = $_POST['operation'];
switch ($operation) {
case 'add':
$result = $num1 + $num2;
break;
case 'subtract':
$result = $num1 - $num2;
break;
case 'multiply':
$result = $num1 * $num2;
break;
case 'divide':
if ($num2 == 0) {
$errors[] = "除数不能为零";
} else {
$result = $num1 / $num2;
}
break;
}
}
}
?>
<!DOCTYPE html>
<html>
<head>
<title>PHP计算器</title>
<style>
.error { color: red; }
</style>
</head>
<body>
<?php foreach ($errors as $error): ?>
<p class="error"><?php echo $error; ?></p>
<?php endforeach; ?>
<form method="post">
<input type="number" step="any" name="num1" required>
<select name="operation">
<option value="add">+</option>
<option value="subtract">-</option>
<option value="multiply">×</option>
<option value="divide">÷</option>
</select>
<input type="number" step="any" name="num2" required>
<button type="submit">计算</button>
</form>
<?php if ($result !== ''): ?>
<p>结果: <?php echo $result; ?></p>
<?php endif; ?>
</body>
</html>主要功能说明
- 支持基本的加减乘除运算
- 包含输入验证和错误处理
- 防止除数为零的错误
- 支持浮点数运算（通过step="any"属性）
- 简单的CSS样式增强显示效果
这段代码可以保存为.php文件并在支持PHP的服务器上运行，创建一个功能完整的网页计算器。
