前言
PHP（Hypertext Preprocessor）是 Web 开发领域最成熟的语言之一。全球超过 75% 的网站使用 PHP，包括 WordPress、Facebook（早期）、Wikipedia。PHP 以部署简单、生态成熟、开发速度快著称。
本文将从零开始，带你系统掌握 PHP 的核心基础。
为什么选择 PHP？
| 优势 |
说明 |
| 🚀 即写即用 |
无需编译，保存即生效 |
| 🌐 为 Web 而生 |
天然支持 HTML 混写，处理表单、Cookie、Session 极方便 |
| 📦 生态成熟 |
Composer + Packagist 海量类库 |
| 💰 成本低 |
几乎所有虚拟主机都支持，云服务器部署简单 |
| 🎯 框架丰富 |
Laravel、Symfony、ThinkPHP 等 |
一、环境搭建
1.1 安装 PHP
Windows：下载 XAMPP 或 PHPStudy
Linux：
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| sudo apt install php php-cli php-fpm php-mysql php-curl php-mbstring
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macOS：
1.2 验证安装
1.3 运行 PHP 代码
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php hello.php
php -S localhost:8000
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二、第一个 PHP 程序
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| <!DOCTYPE html>
<html>
<head>
<title>第一个 PHP 程序</title>
</head>
<body>
<h1><?php echo "Hello, 七月小站!"; ?></h1>
<p>现在时间是: <?php echo date("Y-m-d H:i:s"); ?></p>
</body>
</html>
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💡 PHP 文件可以混合 HTML 和 PHP 代码。<?php ... ?> 标签内的代码在服务端执行，生成 HTML 后返回浏览器。
三、变量与数据类型
3.1 变量
PHP 变量以 $ 开头，松类型：
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| <?php
$name = "July";
$age = 25;
$height = 1.75;
$isActive = true;
$varName = "age";
echo $$varName;
$a = 10;
$b = &$a;
$b = 20;
echo $a;
echo $name;
var_dump($age);
print_r($name);
echo "姓名: {$name}, 年龄: {$age}";
echo '姓名: ' . $name;
?>
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3.2 数据类型
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$int = 42;
$float = 3.14;
$string = "Hello";
$bool = true;
$array = [1, 2, 3];
$object = new stdClass();
$null = null;
echo gettype($int);
echo is_int($int) ? "是整数" : "不是整数";
$strNum = (string) $int;
$intNum = (int) "123";
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3.3 字符串操作
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| $str = "Hello, PHP!";
echo strlen($str);
echo strpos($str, "PHP");
echo str_replace("PHP", "World", $str);
echo strtoupper($str);
echo strtolower($str);
echo substr($str, 0, 5);
echo trim(" hello ");
echo str_contains($str, "PHP");
echo str_starts_with($str, "Hel");
echo str_ends_with($str, "!");
$parts = explode(", ", $str);
$joined = implode(" - ", $parts);
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四、数组（PHP 的核心数据结构）⭐
4.1 索引数组
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$fruits = ["苹果", "香蕉", "橘子"];
$fruits = array("苹果", "香蕉", "橘子");
$nums = range(1, 5);
echo $fruits[0];
$fruits[] = "草莓";
array_push($fruits, "葡萄");
array_unshift($fruits, "西瓜");
$last = array_pop($fruits);
$first = array_shift($fruits);
unset($fruits[1]);
foreach ($fruits as $fruit) {
echo $fruit . " ";
}
foreach ($fruits as $index => $fruit) {
echo "{$index}: {$fruit}\n";
}
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4.2 关联数组（类似字典/Map）
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| $person = [
"name" => "July",
"age" => 25,
"city" => "深圳",
"hobbies" => ["编程", "阅读", "摄影"]
];
echo $person["name"];
echo $person["hobbies"][0];
$person["email"] = "july@example.com";
unset($person["city"]);
if (array_key_exists("age", $person)) {
echo "age 已设置";
}
if (isset($person["age"])) {
echo "age 已设置";
}
foreach ($person as $key => $value) {
echo "{$key}: {$value}\n";
}
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4.3 常用数组函数
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| $nums = [3, 1, 4, 1, 5, 9, 2, 6];
echo count($nums);
echo array_sum($nums);
echo max($nums);
echo min($nums);
sort($nums);
rsort($nums);
asort($person);
ksort($person);
$evens = array_filter($nums, function($n) {
return $n % 2 == 0;
});
$doubled = array_map(function($n) {
return $n * 2;
}, $nums);
$a = ["a" => 1, "b" => 2];
$b = ["b" => 3, "c" => 4];
$merged = array_merge($a, $b);
$spread = [...$a, ...$b];
$unique = array_unique([1, 2, 2, 3, 3, 3]);
$reversed = array_reverse($nums);
$hasCommon = !empty(array_intersect([1, 2], [2, 3]));
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五、流程控制
5.1 if / else
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| $score = 85;
if ($score >= 90) {
$grade = "A";
} elseif ($score >= 80) {
$grade = "B";
} elseif ($score >= 60) {
$grade = "C";
} else {
$grade = "D";
}
echo "等级: {$grade}";
$status = ($age >= 18) ? "成年" : "未成年";
$name = $_GET["name"] ?? "访客";
$config ??= "default";
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5.2 match 表达式（PHP 8.0+，替代 switch）
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$day = 3;
$dayName = match ($day) {
1 => "星期一",
2 => "星期二",
3 => "星期三",
4 => "星期四",
5 => "星期五",
6, 7 => "周末",
default => "无效"
};
echo $dayName;
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5.3 传统 switch
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| switch ($day) {
case 1:
echo "星期一";
break;
case 2:
echo "星期二";
break;
default:
echo "其他";
}
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5.4 循环
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for ($i = 0; $i < 5; $i++) {
echo $i . " ";
}
$count = 0;
while ($count < 5) {
echo $count . " ";
$count++;
}
do {
echo "执行";
} while (false);
$fruits = ["苹果", "香蕉", "橘子"];
foreach ($fruits as $fruit) {
echo $fruit . "\n";
}
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六、函数
6.1 基本函数
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function greet($name) {
return "你好，{$name}！";
}
function add($a, $b = 10) {
return $a + $b;
}
function multiply(int $a, int $b): int {
return $a * $b;
}
function getUser(?int $id): ?array {
if ($id === null) return null;
return ["id" => $id, "name" => "July"];
}
echo add(b: 5, a: 3);
function sumAll(...$nums) {
return array_sum($nums);
}
echo sumAll(1, 2, 3, 4, 5);
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6.2 匿名函数（闭包）
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$double = function($x) {
return $x * 2;
};
echo $double(5);
$multiplier = 3;
$triple = function($x) use ($multiplier) {
return $x * $multiplier;
};
echo $triple(5);
$multiplier = 3;
$triple = fn($x) => $x * $multiplier;
echo $triple(5);
$nums = [1, 2, 3, 4, 5];
$doubled = array_map(fn($n) => $n * 2, $nums);
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6.3 变量作用域
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| $globalVar = "全局变量";
function test() {
$localVar = "局部变量";
global $globalVar;
echo $globalVar;
echo $GLOBALS["globalVar"];
}
function counter() {
static $count = 0;
$count++;
return $count;
}
echo counter();
echo counter();
echo counter();
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七、面向对象编程（OOP）
7.1 类与对象
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| class User
{
public string $username;
public string $email;
private string $password;
protected int $age;
public static int $count = 0;
const ROLE_USER = "user";
const ROLE_ADMIN = "admin";
public function __construct(
string $username,
string $email,
string $password,
int $age = 18
) {
$this->username = $username;
$this->email = $email;
$this->password = password_hash($password, PASSWORD_DEFAULT);
$this->age = $age;
self::$count++;
}
public function getAge(): int
{
return $this->age;
}
public function setAge(int $age): void
{
if ($age < 0 || $age > 150) {
throw new InvalidArgumentException("无效的年龄");
}
$this->age = $age;
}
public function greet(): string
{
return "你好，我是{$this->username}";
}
public function verifyPassword(string $password): bool
{
return password_verify($password, $this->password);
}
public static function getCount(): int
{
return self::$count;
}
public function __destruct()
{
}
public function __toString(): string
{
return "User({$this->username})";
}
}
$user1 = new User("July", "july@example.com", "secret123", 25);
$user2 = new User("zhangsan", "zhangsan@example.com", "pass456");
echo $user1->greet();
echo User::$count;
echo User::ROLE_ADMIN;
echo $user1;
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7.2 继承
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| class Animal
{
public function __construct(
protected string $name
) {}
public function speak(): string
{
return "...";
}
public function getName(): string
{
return $this->name;
}
}
class Dog extends Animal
{
public function __construct(
string $name,
private string $breed
) {
parent::__construct($name);
}
public function speak(): string
{
return "汪汪汪！";
}
public function getBreed(): string
{
return $this->breed;
}
}
class Cat extends Animal
{
public function speak(): string
{
return "喵喵喵！";
}
}
$animals = [
new Dog("旺财", "金毛"),
new Cat("小花"),
];
foreach ($animals as $animal) {
echo "{$animal->getName()} 说: {$animal->speak()}\n";
}
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7.3 接口与抽象类
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interface LoggerInterface
{
public function log(string $message): void;
}
interface FormatterInterface
{
public function format(string $message): string;
}
class FileLogger implements LoggerInterface, FormatterInterface
{
public function __construct(private string $filepath) {}
public function log(string $message): void
{
$formatted = $this->format($message);
file_put_contents($this->filepath, $formatted . "\n", FILE_APPEND);
}
public function format(string $message): string
{
return sprintf("[%s] %s", date("Y-m-d H:i:s"), $message);
}
}
function runApp(LoggerInterface $logger): void {
$logger->log("应用启动");
}
trait Timestampable
{
private \DateTime $createdAt;
private \DateTime $updatedAt;
public function initTimestamps(): void
{
$this->createdAt = new \DateTime();
$this->updatedAt = new \DateTime();
}
public function getCreatedAt(): \DateTime
{
return $this->createdAt;
}
}
class Article
{
use Timestampable;
public function __construct(string $title)
{
$this->initTimestamps();
}
}
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八、表单处理
PHP 处理表单是最常见的 Web 开发场景。
8.1 HTML 表单
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<form action="submit.php" method="POST" enctype="multipart/form-data">
<label>姓名：<input type="text" name="username" required></label><br>
<label>邮箱：<input type="email" name="email"></label><br>
<label>年龄：<input type="number" name="age" min="1" max="150"></label><br>
<label>性别：
<input type="radio" name="gender" value="male"> 男
<input type="radio" name="gender" value="female"> 女
</label><br>
<label>爱好：
<input type="checkbox" name="hobbies[]" value="coding"> 编程
<input type="checkbox" name="hobbies[]" value="reading"> 阅读
<input type="checkbox" name="hobbies[]" value="sports"> 运动
</label><br>
<label>个人简介：<textarea name="bio"></textarea></label><br>
<label>头像：<input type="file" name="avatar"></label><br>
<button type="submit">提交</button>
</form>
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8.2 处理表单数据
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| <?php
if ($_SERVER["REQUEST_METHOD"] !== "POST") {
die("只接受 POST 请求");
}
$username = trim($_POST["username"] ?? "");
$email = filter_input(INPUT_POST, "email", FILTER_VALIDATE_EMAIL);
$age = (int) ($_POST["age"] ?? 0);
$gender = $_POST["gender"] ?? "未指定";
$hobbies = $_POST["hobbies"] ?? [];
$bio = strip_tags($_POST["bio"] ?? "");
$errors = [];
if (empty($username)) {
$errors[] = "姓名不能为空";
}
if (!$email) {
$errors[] = "邮箱格式不正确";
}
if ($age < 1 || $age > 150) {
$errors[] = "年龄不合理";
}
if (isset($_FILES["avatar"]) && $_FILES["avatar"]["error"] === UPLOAD_ERR_OK) {
$allowedTypes = ["image/jpeg", "image/png", "image/gif"];
$maxSize = 2 * 1024 * 1024;
$file = $_FILES["avatar"];
if (!in_array($file["type"], $allowedTypes)) {
$errors[] = "只允许 JPG/PNG/GIF 格式";
}
if ($file["size"] > $maxSize) {
$errors[] = "文件不能超过 2MB";
}
if (empty($errors)) {
$ext = pathinfo($file["name"], PATHINFO_EXTENSION);
$newName = uniqid("avatar_") . "." . $ext;
$uploadPath = __DIR__ . "/uploads/" . $newName;
if (!is_dir(__DIR__ . "/uploads")) {
mkdir(__DIR__ . "/uploads", 0755, true);
}
move_uploaded_file($file["tmp_name"], $uploadPath);
echo "头像上传成功: {$newName}<br>";
}
}
if (!empty($errors)) {
foreach ($errors as $error) {
echo "<p style='color:red'>❌ {$error}</p>";
}
exit;
}
echo "<h2>提交成功！</h2>";
echo "<p>姓名: " . htmlspecialchars($username) . "</p>";
echo "<p>邮箱: " . htmlspecialchars($email) . "</p>";
echo "<p>年龄: {$age}</p>";
echo "<p>性别: {$gender}</p>";
echo "<p>爱好: " . implode(", ", $hobbies) . "</p>";
?>
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九、数据库操作（MySQL + PDO）
PDO（PHP Data Objects）是 PHP 访问数据库的统一接口，安全、支持预处理语句。
9.1 数据库连接
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| <?php
function getDB(): PDO {
static $pdo = null;
if ($pdo === null) {
$host = "localhost";
$dbname = "my_blog";
$username = "root";
$password = "your_password";
$charset = "utf8mb4";
$dsn = "mysql:host={$host};dbname={$dbname};charset={$charset}";
$options = [
PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
PDO::ATTR_EMULATE_PREPARES => false,
];
$pdo = new PDO($dsn, $username, $password, $options);
}
return $pdo;
}
?>
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9.2 CRUD 操作
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| <?php
require_once "database.php";
$db = getDB();
$stmt = $db->prepare("INSERT INTO users (username, email, password) VALUES (?, ?, ?)");
$stmt->execute(["July", "july@example.com", password_hash("secret123", PASSWORD_DEFAULT)]);
$newId = $db->lastInsertId();
echo "新增用户 ID: {$newId}<br>";
$stmt = $db->prepare("INSERT INTO users (username, email, password) VALUES (:name, :email, :pass)");
$stmt->execute([
":name" => "zhangsan",
":email" => "zhangsan@example.com",
":pass" => password_hash("pass456", PASSWORD_DEFAULT),
]);
$stmt = $db->query("SELECT id, username, email, created_at FROM users ORDER BY id DESC");
$users = $stmt->fetchAll();
foreach ($users as $user) {
echo "{$user["id"]}: {$user["username"]} ({$user["email"]})<br>";
}
$stmt = $db->prepare("SELECT * FROM users WHERE username = ?");
$stmt->execute(["July"]);
$user = $stmt->fetch();
if ($user) {
echo "找到用户: {$user["username"]}<br>";
}
$page = (int) ($_GET["page"] ?? 1);
$perPage = 10;
$offset = ($page - 1) * $perPage;
$stmt = $db->prepare("SELECT * FROM users ORDER BY id DESC LIMIT ? OFFSET ?");
$stmt->execute([$perPage, $offset]);
$users = $stmt->fetchAll();
$total = $db->query("SELECT COUNT(*) FROM users")->fetchColumn();
$totalPages = ceil($total / $perPage);
$stmt = $db->prepare("UPDATE users SET email = ?, updated_at = NOW() WHERE id = ?");
$stmt->execute(["new_email@example.com", $newId]);
echo "更新了 {$stmt->rowCount()} 行<br>";
$stmt = $db->prepare("DELETE FROM users WHERE id = ?");
$stmt->execute([$newId]);
echo "删除了 {$stmt->rowCount()} 行<br>";
?>
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9.3 安全查询要点
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$username = $_GET["username"];
$db->query("SELECT * FROM users WHERE username = '{$username}'");
$stmt = $db->prepare("SELECT * FROM users WHERE username = ?");
$stmt->execute([$_GET["username"]]);
$ids = [1, 2, 3, 4, 5];
$placeholders = implode(",", array_fill(0, count($ids), "?"));
$stmt = $db->prepare("SELECT * FROM users WHERE id IN ({$placeholders})");
$stmt->execute($ids);
$keyword = $_GET["q"] ?? "";
$stmt = $db->prepare("SELECT * FROM posts WHERE title LIKE ?");
$stmt->execute(["%{$keyword}%"]);
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9.4 简单的事务
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| try {
$db->beginTransaction();
$stmt = $db->prepare("INSERT INTO posts (title, content, user_id) VALUES (?, ?, ?)");
$stmt->execute(["文章标题", "文章内容", 1]);
$postId = $db->lastInsertId();
$stmt = $db->prepare("INSERT INTO post_tags (post_id, tag_id) VALUES (?, ?)");
$stmt->execute([$postId, 5]);
$stmt->execute([$postId, 8]);
$db->commit();
echo "文章发布成功！";
} catch (Exception $e) {
$db->rollBack();
echo "发布失败: " . $e->getMessage();
}
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十、Cookie 与 Session
10.1 Cookie（客户端存储）
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setcookie("username", "July", time() + 3600 * 24 * 30, "/");
setcookie("theme", "dark", [
"expires" => time() + 3600 * 24 * 30,
"path" => "/",
"secure" => true, // 仅 HTTPS
"httponly" => true, // JS 无法访问
"samesite" => "Lax",
]);
$username = $_COOKIE["username"] ?? null;
setcookie("username", "", time() - 3600, "/");
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10.2 Session（服务端存储）
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session_start();
$_SESSION["user_id"] = 42;
$_SESSION["username"] = "July";
$_SESSION["logged_in"] = true;
$_SESSION["cart"] = [
["id" => 1, "name" => "商品A", "qty" => 2],
["id" => 2, "name" => "商品B", "qty" => 1],
];
$userName = $_SESSION["username"] ?? "访客";
unset($_SESSION["cart"]);
session_destroy();
session_start();
function isLoggedIn(): bool {
return isset($_SESSION["user_id"]);
}
function requireLogin(): void {
if (!isLoggedIn()) {
header("Location: /login.php");
exit;
}
}
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十一、文件操作与常用函数
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$content = file_get_contents("data.txt");
$lines = file("data.txt");
file_put_contents("output.txt", "Hello World\n");
file_put_contents("output.txt", "追加内容\n", FILE_APPEND);
if (file_exists("data.txt")) {
echo "文件大小: " . filesize("data.txt") . " 字节";
echo "修改时间: " . date("Y-m-d", filemtime("data.txt"));
}
$files = scandir("/path/to/dir");
is_dir("/path");
mkdir("/path/to/newdir", 0755, true);
htmlspecialchars("<script>alert('xss')</script>");
strip_tags("<p>Hello</p><script>evil()</script>");
urlencode("搜索 关键词");
json_encode(["name" => "July"], JSON_UNESCAPED_UNICODE);
json_decode('{"name":"July"}', true);
echo date("Y-m-d H:i:s");
echo date("Y-m-d H:i:s", strtotime("+1 week"));
echo time();
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十二、实战：简易博客 API
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| <?php
header("Content-Type: application/json; charset=utf-8");
header("Access-Control-Allow-Origin: *");
header("Access-Control-Allow-Methods: GET, POST, PUT, DELETE, OPTIONS");
header("Access-Control-Allow-Headers: Content-Type");
if ($_SERVER["REQUEST_METHOD"] === "OPTIONS") {
http_response_code(200);
exit;
}
require_once "database.php";
$db = getDB();
$method = $_SERVER["REQUEST_METHOD"];
$path = parse_url($_SERVER["REQUEST_URI"], PHP_URL_PATH);
if (preg_match('#^/api/articles$#', $path)) {
switch ($method) {
case "GET":
$stmt = $db->query("SELECT * FROM posts WHERE status = 1 ORDER BY id DESC LIMIT 20");
$articles = $stmt->fetchAll();
echo json_encode(["code" => 200, "data" => $articles], JSON_UNESCAPED_UNICODE);
break;
case "POST":
$input = json_decode(file_get_contents("php://input"), true);
if (empty($input["title"]) || empty($input["content"])) {
http_response_code(400);
echo json_encode(["code" => 400, "msg" => "标题和内容不能为空"]);
exit;
}
$stmt = $db->prepare("INSERT INTO posts (title, content, user_id) VALUES (?, ?, ?)");
$stmt->execute([$input["title"], $input["content"], $input["user_id"] ?? 1]);
echo json_encode([
"code" => 201,
"msg" => "创建成功",
"id" => $db->lastInsertId()
], JSON_UNESCAPED_UNICODE);
break;
default:
http_response_code(405);
echo json_encode(["code" => 405, "msg" => "方法不允许"]);
}
}
elseif (preg_match('#^/api/articles/(\d+)$#', $path, $matches)) {
$id = (int) $matches[1];
switch ($method) {
case "GET":
$stmt = $db->prepare("SELECT * FROM posts WHERE id = ?");
$stmt->execute([$id]);
$article = $stmt->fetch();
if (!$article) {
http_response_code(404);
echo json_encode(["code" => 404, "msg" => "文章不存在"]);
exit;
}
echo json_encode(["code" => 200, "data" => $article], JSON_UNESCAPED_UNICODE);
break;
case "PUT":
$input = json_decode(file_get_contents("php://input"), true);
$stmt = $db->prepare("UPDATE posts SET title = ?, content = ?, updated_at = NOW() WHERE id = ?");
$stmt->execute([$input["title"], $input["content"], $id]);
echo json_encode(["code" => 200, "msg" => "更新成功"]);
break;
case "DELETE":
$stmt = $db->prepare("DELETE FROM posts WHERE id = ?");
$stmt->execute([$id]);
echo json_encode(["code" => 200, "msg" => "删除成功"]);
break;
default:
http_response_code(405);
echo json_encode(["code" => 405, "msg" => "方法不允许"]);
}
}
else {
http_response_code(404);
echo json_encode(["code" => 404, "msg" => "路由不存在"]);
}
?>
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启动并测试：
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| php -S localhost:8000
curl http://localhost:8000/api/articles
curl -X POST http://localhost:8000/api/articles \
-H "Content-Type: application/json" \
-d '{"title":"PHP基础教程","content":"这是内容","user_id":1}'
curl http://localhost:8000/api/articles/1
curl -X PUT http://localhost:8000/api/articles/1 \
-H "Content-Type: application/json" \
-d '{"title":"PHP进阶教程","content":"更新的内容"}'
curl -X DELETE http://localhost:8000/api/articles/1
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十三、Composer 与第三方库
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curl -sS https://getcomposer.org/installer | php
sudo mv composer.phar /usr/local/bin/composer
composer init
composer require phpmailer/phpmailer
composer require monolog/monolog
composer install
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| <?php
require_once "vendor/autoload.php";
use Monolog\Logger;
use Monolog\Handler\StreamHandler;
$log = new Logger("myapp");
$log->pushHandler(new StreamHandler("app.log", Logger::WARNING));
$log->warning("这是一个警告");
$log->error("发生错误", ["user_id" => 42]);
use PHPMailer\PHPMailer\PHPMailer;
$mail = new PHPMailer(true);
$mail->setFrom("from@example.com", "七月小站");
$mail->addAddress("to@example.com");
$mail->Subject = "测试邮件";
$mail->Body = "<h1>Hello</h1><p>这是一封测试邮件</p>";
$mail->isHTML(true);
$mail->send();
?>
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常用 PHP 命令速查
| 命令 |
说明 |
php -v |
查看 PHP 版本 |
php file.php |
运行 PHP 文件 |
php -S localhost:8000 |
启动开发服务器 |
php -m |
列出已安装的扩展模块 |
php -i |
显示 PHP 配置信息（phpinfo） |
php -r "echo 'hello';" |
执行一行 PHP 代码 |
composer install |
安装依赖 |
composer require pkg |
添加新的依赖包 |
安全最佳实践
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echo htmlspecialchars($userInput, ENT_QUOTES, "UTF-8");
$stmt = $db->prepare("SELECT * FROM users WHERE id = ?");
$stmt->execute([$id]);
session_start();
if ($_SERVER["REQUEST_METHOD"] === "POST") {
if ($_POST["csrf_token"] !== $_SESSION["csrf_token"]) {
die("CSRF 验证失败");
}
}
$_SESSION["csrf_token"] = bin2hex(random_bytes(32));
$hashed = password_hash($password, PASSWORD_DEFAULT);
password_verify($inputPassword, $hashed);
$allowed = ["image/jpeg", "image/png"];
$finfo = finfo_open(FILEINFO_MIME_TYPE);
$mime = finfo_file($finfo, $_FILES["file"]["tmp_name"]);
if (!in_array($mime, $allowed)) { die("不允许的文件类型"); }
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进一步学习
- Web 框架：Laravel（全栈）、Symfony（企业级）、ThinkPHP（国产）
- CMS：WordPress 主题/插件开发
- 模板引擎：Blade（Laravel）、Twig（Symfony）
- 测试：PHPUnit
- 设计模式：工厂模式、单例模式、依赖注入等在 PHP 中的实践
结语
PHP 作为互联网的”老黄牛”，支撑着全球 75% 以上的网站。它上手简单、部署方便、生态丰富，非常适合快速开发 Web 应用。
本文涵盖了 PHP 开发中最核心的知识点。配合现代 PHP 8.x 的新特性（命名参数、match 表达式、类型系统、JIT 编译器等），PHP 的开发体验已经今非昔比。
别听别人说”PHP 是最好的语言”或”PHP 已死”——自己去写个小项目感受一下吧！🐘
