1. 基本的 PHP 语法
<?php
echo "Hello, World!";
?>
2. 变量和数据类型
<?php
$name = "Alice";
$age = 25;
$isStudent = true;
echo "Name: $name, Age: $age, Student: " . ($isStudent ? "Yes" : "No");
?>
3. 数组
<?php
$fruits = array("Apple", "Banana", "Cherry");
foreach ($fruits as $fruit) {
echo $fruit . "<br>";
}
?>
4. 函数
<?php
function add($a, $b) {
return $a + $b;
}
echo "Sum: " . add(5, 10);
?>
5. 条件语句
<?php
$score = 85;
if ($score >= 90) {
echo "Grade: A";
} elseif ($score >= 80) {
echo "Grade: B";
} else {
echo "Grade: C";
}
?>
6. 表单处理
<!DOCTYPE html>
<html>
<body>
<form method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>">
Name: <input type="text" name="name">
<input type="submit">
</form>
<?php
if ($_SERVER["REQUEST_METHOD"] == "POST") {
$name = htmlspecialchars($_POST['name']);
echo "Hello, $name!";
}
?>
</body>
</html>
7. 连接数据库 (MySQL)
<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "database";
// 创建连接
$conn = new mysqli($servername, $username, $password, $dbname);
// 检查连接
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql = "SELECT id, name FROM users";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
// 输出数据
while($row = $result->fetch_assoc()) {
echo "id: " . $row["id"]. " - Name: " . $row["name"]. "<br>";
}
} else {
echo "0 results";
}
$conn->close();
?>
8. 简单的 REST API
<?php
header("Content-Type: application/json");
$data = [
["id" => 1, "name" => "Alice"],
["id" => 2, "name" => "Bob"],
];
echo json_encode($data);
?>
9. 使用 Composer 管理依赖
在项目根目录下创建 composer.json 文件：
{
"require": {
"monolog/monolog": "^2.0"
}
}
然后在命令行中运行：
composer install
本文作者：GT工作室
如有疑问联系qq：3771822731
标签：基础知识,name,Grade,精推版,echo,PHP,id,conn,row From： https://blog.csdn.net/2401_82990204/article/details/141371706