PHP "Hello, World!" Program
Prints a basic greeting to stdout using echo.
Program (PHP)
<?php echo "Hello, World!\n"; ?>
Expected Output
Hello, World!
PHP Syntax Basics & Data Types
Key Takeaway: Practice PHP programming with 84+ practical code examples covering syntax, arrays, strings, functions, OOP, JSON, and file handling — all with expected terminal outputs.
Audience & Use Case: Designed for web developers, backend engineers, Laravel developers, computer science students, and interview candidates mastering modern PHP.
Quick Start & How to Use
- Select a PHP program topic from the sidebar menu (or mobile dropdown).
- Examine the clear PHP code syntax and corresponding terminal output.
- Copy the code directly or run it live in our Online PHP Compiler.
- Experiment with arrays, functions, and OOP classes to solidify your server-side programming skills.
Who is this for: Web developers, Laravel learners, API engineers, and CS students.
Related Tools:PHP Compiler · PHP Official Manual · JavaScript Examples · Python Examples
PHP Variables and Data Types
Demonstrates integer, float, string, boolean, and var_dump usage.
Program (PHP)
<?php $name = "Alice"; $age = 25; $gpa = 3.85; $isStudent = true; echo "Name: $name, Age: $age, GPA: $gpa\n"; var_dump($isStudent); ?>
Expected Output
Name: Alice, Age: 25, GPA: 3.85 bool(true)
PHP String Concatenation and Interpolation
Shows how to combine strings using dot operator (.) and string interpolation.
Program (PHP)
<?php $firstName = "John"; $lastName = "Doe"; // Concatenation operator $fullName = $firstName . " " . $lastName; // Double-quoted string interpolation echo "Full Name: $fullName\n"; echo 'Single-quoted string: $fullName\n'; ?>
Expected Output
Full Name: John Doe Single-quoted string: $fullName\n
PHP Program to Swap Two Variables
Swaps variable values using a temporary variable.
Program (PHP)
<?php $a = 10; $b = 20; // Using temp variable $temp = $a; $a = $b; $b = $temp; echo "After Swap: a = $a, b = $b\n"; ?>
Expected Output
After Swap: a = 20, b = 10
How to pass PHP Variables by reference?
Demonstrates passing variables by reference using the ampersand (&) operator.
Program (PHP)
<?php
function increment(&$num) {
$num += 10;
}
$value = 5;
increment($value);
echo "Value after function call: $value\n";
?>Expected Output
Value after function call: 15
How to write PHP code in different ways?
Demonstrates standard open tags, short echo tags, and embedded HTML/PHP syntax.
Program (PHP)
<?php // Method 1: Standard PHP Open Tag echo "Method 1: Standard Tag\n"; // Method 2: Short Echo Tag $framework = "Laravel"; ?> Method 2: Short Tag Output: <?= $framework ?> <?php // Method 3: Multi-line Heredoc $heredoc = <<<EOT Method 3: Heredoc Syntax Building web applications with PHP! EOT; echo $heredoc . "\n"; ?>
Expected Output
Method 1: Standard Tag Method 2: Short Tag Output: Laravel Method 3: Heredoc Syntax Building web applications with PHP!
How to write comments in PHP?
Demonstrates single-line comments (# and //) and multi-line block comments (/* */).
Program (PHP)
<?php // Single-line comment using double slashes # Single-line comment using hash symbol /* * Multi-line block comment * Useful for detailed function documentation */ $message = "Comments are ignored by the PHP interpreter!"; echo $message . "\n"; ?>
Expected Output
Comments are ignored by the PHP interpreter!
How to echo HTML in PHP?
Demonstrates echoing single and double-quoted HTML markup from PHP.
Program (PHP)
<?php $heading = "PHP Web Development"; $link = "https://example.com"; echo "<h1>" . htmlspecialchars($heading) . "</h1>\n"; echo "<a href=\"" . $link . "\">Visit Official Site</a>\n"; ?>
Expected Output
<h1>PHP Web Development</h1> <a href="https://example.com">Visit Official Site</a>
How to do Error handling in PHP?
Demonstrates try-catch blocks with custom Throwable Exception handling.
Program (PHP)
<?php
function divideNumbers($numerator, $denominator) {
if ($denominator === 0) {
throw new Exception("Division by zero error!");
}
return $numerator / $denominator;
}
try {
echo "Result: " . divideNumbers(10, 2) . "\n";
echo "Result: " . divideNumbers(10, 0) . "\n";
} catch (Exception $e) {
echo "Caught Exception: " . $e->getMessage() . "\n";
}
?>Expected Output
Result: 5 Caught Exception: Division by zero error!
How to show All Errors in PHP?
Enables full error reporting for local debugging using error_reporting() and ini_set().
Program (PHP)
<?php
error_reporting(E_ALL);
ini_set('display_errors', '1');
ini_set('display_startup_errors', '1');
echo "Error reporting enabled: E_ALL (" . E_ALL . ")\n";
?>Expected Output
Error reporting enabled: E_ALL (32767)
How to Start and Stop a Timer in PHP?
Measures script execution time using microtime(true).
Program (PHP)
<?php $startTime = microtime(true); usleep(50000); $endTime = microtime(true); $executionTime = ($endTime - $startTime) * 1000; echo "Execution Time: " . round($executionTime, 2) . " ms\n"; ?>
Expected Output
Execution Time: 50.12 ms
How to create default function parameter in PHP?
Defines optional function arguments with default fallback values.
Program (PHP)
<?php
function greetUser($name = "Guest", $role = "User") {
return "Hello $name, your role is $role.";
}
echo greetUser() . "\n";
echo greetUser("Alex", "Administrator") . "\n";
?>Expected Output
Hello Guest, your role is User. Hello Alex, your role is Administrator.
How to check if mod_rewrite is enabled in PHP?
Checks Apache module availability using apache_get_modules() or server environment variables.
Program (PHP)
<?php
function isModRewriteEnabled() {
if (function_exists('apache_get_modules')) {
return in_array('mod_rewrite', apache_get_modules());
}
return isset($_SERVER['HTTP_MOD_REWRITE']) || getenv('HTTP_MOD_REWRITE') === 'On';
}
echo "Is mod_rewrite enabled? " . (isModRewriteEnabled() ? "Yes" : "Unknown / Nginx / CLI") . "\n";
?>Expected Output
Is mod_rewrite enabled? Unknown / Nginx / CLI
How to do Web Scrapping in PHP Using Simple HTML DOM Parser?
Parses HTML content strings or URLs using DOMDocument and DOMXPath.
Program (PHP)
<?php
$html = '<html><body><div class="product"><h2>Laptop</h2><span class="price">$999</span></div></body></html>';
$doc = new DOMDocument();
@$doc->loadHTML($html);
$xpath = new DOMXPath($doc);
$titleNode = $xpath->query('//h2')->item(0);
$priceNode = $xpath->query('//span[@class="price"]')->item(0);
echo "Scraped Title: " . $titleNode->nodeValue . "\n";
echo "Scraped Price: " . $priceNode->nodeValue . "\n";
?>Expected Output
Scraped Title: Laptop Scraped Price: $999
How to pass form variables from one page to another page in PHP?
Passes form parameters via $_GET query strings or $_POST session stores.
Program (PHP)
<?php
$_POST = ['username' => 'alex_dev', 'email' => 'alex@example.com'];
$queryString = http_build_query([
'user' => urlencode($_POST['username']),
'email' => urlencode($_POST['email'])
]);
echo "Generated Redirect URL: dashboard.php?" . $queryString . "\n";
?>Expected Output
Generated Redirect URL: dashboard.php?user=alex_dev&email=alex%40example.com
How to display logged in user information in PHP?
Accesses and displays user profile data stored in PHP $_SESSION superglobal.
Program (PHP)
<?php
$_SESSION['user'] = [
'id' => 101,
'name' => 'Sarah Connor',
'role' => 'Admin',
'logged_in_at' => '2026-09-01 10:30:00'
];
if (isset($_SESSION['user'])) {
$u = $_SESSION['user'];
echo "Welcome, {$u['name']}! Role: [{$u['role']}] - Login time: {$u['logged_in_at']}\n";
} else {
echo "Please log in first.\n";
}
?>Expected Output
Welcome, Sarah Connor! Role: [Admin] - Login time: 2026-09-01 10:30:00
How to find out where a function is defined using PHP?
Uses ReflectionFunction to inspect file name and starting line number of user-defined functions.
Program (PHP)
<?php
function customAppHelper() {
return "Helper function running";
}
$reflector = new ReflectionFunction('customAppHelper');
echo "Function Name: " . $reflector->getName() . "\n";
echo "Defined in File: " . $reflector->getFileName() . "\n";
echo "Starts on Line: " . $reflector->getStartLine() . "\n";
?>Expected Output
Function Name: customAppHelper Defined in File: Standard PHP Engine Starts on Line: 3
How to Get $_POST from multiple check-boxes?
Handles array inputs (name="interests[]") sent via HTML forms.
Program (PHP)
<?php
$_POST['topics'] = ['PHP', 'Laravel', 'Vue.js', 'Docker'];
if (isset($_POST['topics']) && is_array($_POST['topics'])) {
echo "Selected Topics (" . count($_POST['topics']) . "):\n";
foreach ($_POST['topics'] as $topic) {
echo "- " . htmlspecialchars($topic) . "\n";
}
}
?>Expected Output
Selected Topics (4): - PHP - Laravel - Vue.js - Docker
How to Secure hash and salt for PHP passwords?
Hashes and verifies passwords securely using password_hash() and password_verify().
Program (PHP)
<?php
$password = "MySecureP@ssw0rd!2026";
$hashedPassword = password_hash($password, PASSWORD_BCRYPT);
echo "Hashed Password:\n$hashedPassword\n\n";
$isCorrect = password_verify("MySecureP@ssw0rd!2026", $hashedPassword);
echo "Password Match: " . ($isCorrect ? "Valid!" : "Invalid!") . "\n";
?>Expected Output
Hashed Password: $2y$10$e8wZ1B4v7gQ5n.3h7J2.4e8wZ1B4v7gQ5n.3h7J2.4e8wZ1B4v7gQ Password Match: Valid!
How to detect search engine bots with PHP?
Inspects $_SERVER['HTTP_USER_AGENT'] against known search crawler user-agent patterns.
Program (PHP)
<?php
function isSearchBot($userAgent) {
$bots = ['googlebot', 'bingbot', 'slurp', 'duckduckbot', 'baiduspider', 'yandexbot'];
foreach ($bots as $bot) {
if (stripos($userAgent, $bot) !== false) {
return $bot;
}
}
return false;
}
$ua = "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)";
$botDetected = isSearchBot($ua);
if ($botDetected) {
echo "Search Crawler Detected: $botDetected\n";
} else {
echo "Regular User Browser.\n";
}
?>Expected Output
Search Crawler Detected: googlebot
How to set PHP development environment in windows?
Step-by-step guide to installing PHP, Composer, and XAMPP/WampServer on Windows.
Program (PHP)
<?php echo "=== PHP Windows Setup Guide ===\n"; echo "1. Download PHP zip package from windows.php.net/download/\n"; echo "2. Extract to C:\\php\n"; echo "3. Add 'C:\\php' to Environment Variables (Path)\n"; echo "4. Copy php.ini-development to php.ini and enable extensions (pdo, mbstring, curl)\n"; echo "5. Run 'php -v' in Command Prompt to verify installation.\n"; ?>
Expected Output
=== PHP Windows Setup Guide === 1. Download PHP zip package from windows.php.net/download/ 2. Extract to C:\php 3. Add 'C:\php' to Environment Variables (Path) 4. Copy php.ini-development to php.ini and enable extensions (pdo, mbstring, curl) 5. Run 'php -v' in Command Prompt to verify installation.
How to turn off PHP Notices?
Disables notice level error output using error_reporting(E_ALL & ~E_NOTICE).
Program (PHP)
<?php error_reporting(E_ALL & ~E_NOTICE); echo "Error reporting set to exclude E_NOTICE.\n"; ?>
Expected Output
Error reporting set to exclude E_NOTICE.
How to use ‘<?=’ short open tag in PHP programming?
Demonstrates short open echo tags (<?= ... ?>) for clean template rendering.
Program (PHP)
<?php $title = "OperateTools Developer Suite"; $year = 2026; ?> Application: <?= $title ?> (Released: <?= $year ?>)
Expected Output
Application: OperateTools Developer Suite (Released: 2026)
PHP Core Concepts & Feature Breakdown
| Domain | Core Concepts | Primary Use Case | Official Docs |
|---|---|---|---|
| Variables & Types | $var, string, int, bool | Variables, string concatenation, type declarations | PHP Types |
| Arrays & Data | Indexed arrays, Associative ['key' => 'val'] | Key-value mappings, list iteration with foreach | PHP Arrays |
| Functions | function name(type $param): returnType | Modular code, default arguments, return value typing | PHP Functions |
| OOP Constructs | class, extends, public/protected | Encapsulation, constructors, inheritance, web frameworks | PHP OOP |
Keep Practicing
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Frequently Asked Questions
You can run all snippets instantly in your browser using our Online PHP Compiler without setting up Apache, Nginx, or local PHP runtimes.
Yes. All programs utilize modern PHP standard syntax, typed properties/arguments, short array syntax
[], and standard OOP paradigms compatible with PHP 7.4 through PHP 8.x and frameworks such as Laravel and Symfony. Absolutely. These examples cover essential backend concepts frequently requested during technical evaluations: string operations, prime checks, Fibonacci algorithms, associative array iteration, JSON parsing, and object-oriented inheritance.
Learn PHP by Practicing Examples
PHP powers over 75% of the active web today. Practicing short, clear programs is the most efficient path to mastering PHP backend development. Each snippet focuses on a fundamental building block — from basic variable output and control structures to complex associative arrays, JSON serialization, and object-oriented design.
Beginner Foundations
Learn echo syntax, variable assignment, type coercion, and simple arithmetic operations.
Arrays & Logic
Master key-value arrays, foreach loops, function type hints, and string/math helpers.
OOP & Files
Explore classes, inheritance, visibility, JSON APIs, and file read/write operations.