What can PHP do for you? Detailed introduction to the functions and features of PHP

PHP is a popular server-side scripting language used to develop dynamic web pages and websites. It is rich in features and functionality, allowing developers to build powerful websites and applications quickly and flexibly. The functional features of PHP will be introduced in detail below, with specific code examples to better understand its use and implementation.

1. Dynamic web page generation

PHP can generate dynamic web page content so that users can see real-time updated pages when they visit. By combining with HTML, you can easily output text, images, forms and other content.

<?php
echo "<h1>欢迎访问我们的网站！</h1>";
?>

2. Processing form data

PHP is often used to process data submitted by HTML forms, verify and process the content entered by the user, and The results are output to the page or database.

<?php
if ($_SERVER["REQUEST_METHOD"] == "POST") {
    $name = $_POST['name'];
    $email = $_POST['email'];
    // 处理表单数据
}
?>

3. Database connection and operation

PHP supports connection and operation with a variety of database systems, including MySQL, SQLite, PostgreSQL, etc. Developers can easily perform operations such as query, update, insert, delete, etc.

<?php
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "myDB";

$conn = new mysqli($servername, $username, $password, $dbname);

if ($conn->connect_error) {
    die("数据库连接失败：" . $conn->connect_error);
}

$sql = "SELECT id, name, email FROM users";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
    while($row = $result->fetch_assoc()) {
        echo "ID: " . $row["id"] . " - Name: " . $row["name"] . " - Email: " . $row["email"] . "<br>";
    }
} else {
    echo "0 结果";
}

$conn->close();
?>

4. Session Management

PHP provides session management function, which can track the user's access status, store user information, and realize login in the website Certification etc.

<?php
session_start();

$_SESSION['user_id'] = 123;
$_SESSION['username'] = 'John';

echo "欢迎，" . $_SESSION['username'];
?>

5. File operation

PHP can easily read and write files, including creating, deleting files, reading and writing content wait.

<?php
$file = fopen("example.txt", "r") or die("无法打开文件！");
echo fread($file, filesize("example.txt"));
fclose($file);
?>

In general, PHP is a powerful, flexible and easy-to-use scripting language suitable for building websites and applications of all sizes. Whether you are a beginner or an experienced developer, you can realize your creativity and needs through PHP. If you want to develop dynamic websites, interactive applications or simple scripting tools, PHP can provide you with powerful support.

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