PHP Installation and Setup - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of PHP Version Check

What is the output of this PHP code snippet when run on a properly installed PHP 8.1 environment?

PHP

<?php
 echo PHP_VERSION;
?>

A php_version

B PHP_VERSION

C 8.1.x (where x is the patch version)

D SyntaxError

💡 Hint

PHP_VERSION is a predefined constant that holds the current PHP version as a string.

The PHP predefined constant PHP_VERSION outputs the current PHP version as a string, such as '8.1.0'. It does not output the literal string 'PHP_VERSION'.

❓ Predict Output

intermediate

Result of phpinfo() Function

What does the phpinfo() function output when called in a PHP script?

PHP

<?php
 phpinfo();
?>

A A detailed HTML page showing PHP configuration and environment

B A plain text list of PHP functions

C An error message about undefined function

D Nothing, it returns an empty string

💡 Hint

phpinfo() outputs configuration info about PHP in HTML format.

phpinfo() outputs a detailed HTML page that shows PHP version, configuration, loaded modules, environment variables, and more.

❓ Predict Output

advanced

Behavior of PHP Script Without Closing Tag

What happens if a PHP script file ends without the closing ?> tag?

PHP

<?php
 echo 'Hello, world!';

A The script runs normally and outputs 'Hello, world!'

B Syntax error due to missing closing tag

C The script outputs 'Hello, world!?>'

D The script outputs nothing

💡 Hint

PHP closing tag is optional at the end of a file.

In PHP, the closing ?> tag at the end of a file is optional and omitting it prevents accidental whitespace output. The script runs normally.

❓ Predict Output

advanced

Output of PHP Script with Short Open Tag Disabled

Given the following PHP code and assuming short_open_tag is disabled in php.ini, what will be the output?

PHP

<?php
 echo 'Test';
?>

A Syntax error due to short open tag

B The literal string '<? echo 'Test'; ?>' is output

C No output at all

D The string 'Test' is output

💡 Hint

Short open tags

If short_open_tag is disabled, PHP does not recognize '

🧠 Conceptual

expert

Understanding PHP Configuration File Location

Where does PHP look for its main configuration file (php.ini) by default when installed on a Linux system?

A /usr/local/lib/php.ini

B /var/www/html/php.ini

C /etc/php.ini

D /etc/php/8.1/cli/php.ini

💡 Hint

PHP version and SAPI (like CLI or Apache) affect the php.ini location.

On many Linux systems, PHP stores version-specific configuration files under /etc/php/{version}/{sapi}/php.ini, for example /etc/php/8.1/cli/php.ini for CLI PHP 8.1.

Practice

1. What is the primary purpose of installing PHP on your computer?

easy

A. To design website layouts with CSS

B. To create databases for storing data

C. To run PHP scripts and develop web applications

D. To edit images and graphics

Solution

1. Step 1: Understand PHP's role

   PHP is a server-side scripting language used to create dynamic web pages and applications.

2. Step 2: Identify installation purpose

   Installing PHP allows your computer to process and run PHP scripts.

3. Final Answer:

   To run PHP scripts and develop web applications -> Option C

4. Quick Check:

   PHP installation = run PHP scripts [OK]

Hint: PHP installation lets you run PHP code locally [OK]

Common Mistakes:

• Confusing PHP with database software
• Thinking PHP is for styling websites
• Assuming PHP edits images

2. Which of the following is the correct way to start a PHP script in a file?

easy

A. <?php

B. <script>

C. <php>

D. <?>

Solution

1. Step 1: Recall PHP opening tags

   The standard way to start PHP code is with <?php tag.

2. Step 2: Check other options

   <script> is for JavaScript, <php> is invalid, and <?> is incomplete.

3. Final Answer:

   <?php -> Option A

4. Quick Check:

   PHP scripts start with <?php [OK]

Hint: PHP scripts always start with <?php tag [OK]

Common Mistakes:

• Using JavaScript tags instead of PHP tags
• Omitting 'php' after the opening tag
• Using invalid tags like <php>

3. After installing PHP, you create a file named test.php with this content:

<?php
 echo 'Hello, PHP!';
?>

What will be the output when you run this file in a browser?

medium

A. <?php echo 'Hello, PHP!'; ?>

B. No output

C. Syntax Error

D. Hello, PHP!

Solution

1. Step 1: Understand PHP code execution

   PHP code inside <?php ... ?> runs on the server and outputs the echoed string.

2. Step 2: Predict output in browser

   The browser shows the result of echo 'Hello, PHP!'; which is the text Hello, PHP!.

3. Final Answer:

   Hello, PHP! -> Option D

4. Quick Check:

   PHP echo outputs text to browser [OK]

Hint: PHP echo prints text, not code tags [OK]

Common Mistakes:

• Expecting PHP code to show as text
• Confusing PHP tags with HTML tags
• Thinking PHP causes syntax error here

4. You installed PHP but when running php -v in the terminal, you get an error saying 'command not found'. What is the most likely cause?

medium

A. PHP is not installed or not added to system PATH

B. The PHP script has syntax errors

C. The web server is not running

D. The PHP file has wrong file extension

Solution

1. Step 1: Understand the error message

   'command not found' means the terminal cannot find the PHP program to run.

2. Step 2: Identify common causes

   This usually happens if PHP is not installed or its folder is not added to the system PATH environment variable.

3. Final Answer:

   PHP is not installed or not added to system PATH -> Option A

4. Quick Check:

   Command not found = PHP missing or PATH missing [OK]

Hint: Check PHP installation and PATH if command not found [OK]

Common Mistakes:

• Blaming syntax errors for command line issues
• Thinking web server status affects terminal commands
• Confusing file extension with command availability

5. You want to quickly set up a PHP development environment on your Windows PC without manual configuration. Which option is the best choice?

hard

A. Download only the PHP binary and run scripts manually

B. Install XAMPP which bundles Apache, MySQL, and PHP

C. Install a text editor and write PHP code without server

D. Use a web browser to run PHP files directly

Solution

1. Step 1: Understand setup options

   Manual PHP installation requires configuring a web server and database separately.

2. Step 2: Identify easiest setup

   XAMPP bundles Apache web server, MySQL database, and PHP in one package for easy installation and setup.

3. Final Answer:

   Install XAMPP which bundles Apache, MySQL, and PHP -> Option B

4. Quick Check:

   XAMPP = easiest PHP environment setup [OK]

Hint: Use XAMPP for quick PHP setup with server and database [OK]

Common Mistakes:

• Thinking PHP runs without a server
• Ignoring the need for a web server in PHP development
• Trying to run PHP files directly in browser