Backend Development with PHP

Introduction Setup Basic Concepts Database Integration Best Practices FAQ

1. Introduction

PHP (Hypertext Preprocessor) is a popular server-side scripting language designed for web development but also used as a general-purpose programming language. Its syntax is similar to C, Java, and Perl, making it easy to learn for those familiar with these languages.

In this lesson, we will cover the essentials of backend development using PHP, including setup, basic concepts, and best practices.

2. Setup

To get started with PHP, you need to set up a development environment. Here’s how:

Install a local server environment like XAMPP, WAMP, or MAMP.
Download and install PHP from the official PHP website if your server environment doesn't include it.
Set up your web server (Apache or Nginx) to serve PHP files.
Create a new directory for your project (e.g., my_php_app).

Once you have set this up, you can create a simple PHP file:

<?php
echo "Hello, World!";
?>

3. Basic Concepts

3.1 PHP Syntax

PHP code is embedded within HTML and starts with <?php and ends with ?>. Here’s an example:

<html>
<body>
<?php
echo "Welcome to PHP!";
?>
</body>
</html>

3.2 Variables and Data Types

Variables in PHP start with a dollar sign ($) followed by the variable name. PHP supports multiple data types, including:

String
Integer
Float
Boolean
Array
Object

3.3 Control Structures

PHP supports various control structures including:

If...else statements
Switch statements
Loops (for, while, foreach)

4. Database Integration

PHP integrates seamlessly with databases, most commonly MySQL. Here's a basic example of how to connect to a MySQL database:

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

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

// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}
echo "Connected successfully";
?>

5. Best Practices

5.1 Code Organization

Keep your code organized by following MVC (Model-View-Controller) architecture.

5.2 Security Practices

Ensure to:

Use prepared statements to prevent SQL injection.
Sanitize user inputs.
Use HTTPS for secure data transmission.

5.3 Error Handling

Implement proper error handling using try-catch blocks:

<?php
try {
    // Code that may throw an exception
} catch (Exception $e) {
    echo 'Caught exception: ',  $e->getMessage(), "\n";
}
?>

6. FAQ

What is PHP?

PHP is a server-side scripting language designed primarily for web development but also used as a general-purpose programming language.

How do I start a PHP project?

Set up a local server environment, create a project directory, and start coding with PHP files.

Is PHP secure?

PHP can be secure if best practices are followed, such as input validation and using prepared statements for database interactions.