Objective of learning PHP

• Set up a PHP environment (XAMPP or WAMP).
• Understand basic PHP syntax, variables, and operators.
• Use conditional statements and loops in PHP.
• Handle and validate forms.
• Implement a lab exercise to create and display user data.

What is PHP?

• PHP (Hypertext Preprocessor): A server-side scripting language for web development.
• Explain its role in dynamic websites.

Setting Up a PHP Environment

Install the latest version of the xampp server.

PHP Basics: Syntax, Variables, and Operators

Syntax:

PHP tags: <?php … ?>

Variables:

Declaring variables: $variable_name = value;

Operators:

• Arithmetic: +, -, *, /, %.
• Assignment: =, +=, -=.
• Comparison: ==, !=, >, <.
• Logical: &&, ||, !.
• Examples (5 minutes):

<?php

$num1 = 10;
$num2 = 20;
$sum = $num1 + $num2;
echo "The sum of $num1 and $num2 is $sum.";

?>

Conditional Statements:

• if
• if-else,
• if-elseif-else
• switch

Example:

<?php

$age = 18;
if ($age >= 18) {
     echo "You are eligible to vote.";
} else {
     echo "You are not eligible to vote.";
}

?>

Loops:

• for
• while
• do-while
• foreach

<?php

for ($i = 1; $i <= 5; $i++) {
     echo "Number: $i<br>";
}

?>

Hands-On Practice:

Write a PHP script to print all even numbers between 1 and 20 using a loop.

Form Handling and Validation

Form Handling:

$_GET and $_POST superglobals for accessing form data.

<form action="process.php" method="POST">
     Name: <input type="text" name="name">
     <button type="submit">Submit</button>
</form>

PHP script (process.php):

<?php

$name = $_POST['name'];
echo "Hello, $name!";

?>

Validation:

• Ensure required fields are filled.
• Sanitize user input using htmlspecialchars().

Example:

<?php

if ($_SERVER["REQUEST_METHOD"] == "POST") {
     $name = htmlspecialchars($_POST['name']);
     if (!empty($name)) {
         echo "Hello, $name!";
     } else {
         echo "Name is required!";
     }
}

?>

Lab Exercise:

Create a PHP form to capture user data (e.g., name, email, and age) and display it on another page.