PHP Introduction: Step-by-Step Guide & Best Practices
What is PHP?
PHP (Hypertext Preprocessor) is a widely used open-source scripting language designed for web development. It runs on the server and is embedded in HTML to create dynamic web pages.
Setting Up PHP
Install a Local Server Environment
To run PHP locally, install one of the following:
- XAMPP (Windows, Mac, Linux) – Download Here
- WAMP (Windows) – Download Here
- MAMP (Mac) – Download Here
Verify PHP Installation
After installation, check if PHP is installed:
- Open the command prompt (Windows) or terminal (Mac/Linux).
- Type:
php -v
This should display the PHP version.
Writing Your First PHP Script
- Create a new file:
index.php
- Add the following code:
<?php
echo "Hello, World!";
?>
Save the file in the htdocs
(XAMPP) or www
(WAMP) directory.
Start Apache from your local server.
Open a browser and visit:
arduino
http://localhost/index.php
You should see Hello, World!
PHP Syntax Basics
Variables
$name = "John";
$age = 25;
echo "My name is $name and I am $age years old.";
Data Types
PHP supports:
- Strings (
"Hello"
) - Integers (
100
) - Floats (
10.5
) - Booleans (
true
orfalse
) - Arrays (
["Apple", "Banana"]
) - Objects
Conditional Statements
$score = 75;
if ($score >= 50) {
echo "You passed!";
} else {
echo "You failed!";
}
Loops
for ($i = 1; $i <= 5; $i++) {
echo "Number: $i <br>";
}
Best Practices for Writing PHP Code
Use Meaningful Variable & Function Names
Bad:
$x = 100;
function a() {}
Good:
$userAge = 100;
function calculateTotal() {}
Sanitize User Input to Prevent Security Issues
$username = htmlspecialchars($_POST['username'], ENT_QUOTES, 'UTF-8');
Use Prepared Statements for SQL Queries
$stmt = $conn->prepare("SELECT * FROM users WHERE email = ?");
$stmt->bind_param("s", $email);
$stmt->execute();
Enable Error Reporting for Debugging
error_reporting(E_ALL);
ini_set('display_errors', 1);
Follow PSR Coding Standards
- PSR-1: Basic coding standard
- PSR-2: Coding style guide
- PSR-4: Autoloading standard