1. What is PHP?

PHP (Hypertext Preprocessor) is a server-side scripting language mainly used for web development.

PHP is used to create dynamic web pages and works well with HTML and databases.

2. Features of PHP

• Open-source and free
• Easy to learn
• Works with HTML
• Supports databases like MySQL
• Runs on different platforms

3. Basic PHP Syntax

PHP code is written inside <?php ... ?> tags.

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

4. Variables in PHP

Variables in PHP start with the $ symbol.

<?php
$name = "Alice";
$age = 20;
echo $name;
echo $age;
?>
    

5. Data Types

• String
• Integer
• Float
• Boolean
• Array
• Object

6. Input and Output

PHP commonly uses forms to take input.

<form method="post">
    Name: <input type="text" name="username">
    <input type="submit">
</form>

<?php
echo $_POST["username"];
?>
    

7. Conditional Statements

<?php
$marks = 75;

if ($marks >= 50) {
    echo "Pass";
} else {
    echo "Fail";
}
?>
    

8. Loops

<?php
for ($i = 1; $i <= 5; $i++) {
    echo $i;
}
?>
    

9. Functions

<?php
function add($a, $b) {
    return $a + $b;
}

echo add(5, 3);
?>
    

10. Arrays

<?php
$colors = array("Red", "Green", "Blue");

foreach ($colors as $color) {
    echo $color;
}
?>
    

11. PHP and Databases

PHP is commonly used with MySQL databases.

• User login systems
• Data storage and retrieval
• Dynamic websites

12. Applications of PHP

• Web applications
• Content Management Systems (WordPress)
• E-commerce websites
• Backend APIs