Why file operations matter in PHP - Challenge Your Understanding

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this PHP file write and read code?

Consider the following PHP code that writes to a file and then reads from it. What will be printed?

PHP

<?php
$file = 'test.txt';
file_put_contents($file, "Hello World!");
$content = file_get_contents($file);
echo $content;
?>

A NULL

B test.txt

C Hello World!

D Error: file not found

💡 Hint

file_put_contents writes text to a file, file_get_contents reads it back.

The code writes 'Hello World!' to 'test.txt' and then reads it back, printing the same text.

🧠 Conceptual

intermediate

Why is it important to close a file after opening it in PHP?

Which of the following best explains why closing a file after opening it is important?

A It deletes the file from the disk.

B It frees system resources and ensures data is properly saved.

C It encrypts the file contents automatically.

D It makes the file read-only.

💡 Hint

Think about what happens if too many files stay open.

Closing a file releases system resources and flushes any buffered data to disk, preventing data loss.

🔧 Debug

advanced

What error does this PHP file open code produce?

Look at this PHP code snippet. What error will it cause when run if the file does not exist?

PHP

<?php
$handle = fopen('nofile.txt', 'r');
?>

A Warning: fopen(): failed to open stream: No such file or directory

B Fatal error: Cannot redeclare fopen()

C Parse error: syntax error, unexpected 'fopen'

D No error, file is created automatically

💡 Hint

Opening a file for reading requires the file to exist.

Trying to open a non-existent file for reading causes a warning because the file cannot be found.

📝 Syntax

advanced

Which option correctly appends text to a file in PHP?

You want to add text to the end of a file without deleting existing content. Which code snippet does this correctly?

A <?php fopen('log.txt', 'w'); fwrite("New entry\n"); fclose(); ?>

B <?php file_put_contents('log.txt', "New entry\n"); ?>

C <?php fopen('log.txt', 'r+'); fwrite("New entry\n"); fclose(); ?>

D <?php file_put_contents('log.txt', "New entry\n", FILE_APPEND); ?>

💡 Hint

Appending means adding without removing old content.

Using FILE_APPEND flag with file_put_contents adds text to the file end. Option D overwrites, C and D have syntax or logic errors.

🚀 Application

expert

How many lines will this PHP script write to the file?

This PHP script writes lines to a file inside a loop. How many lines will the file contain after running?

PHP

<?php
$file = 'output.txt';
$handle = fopen($file, 'w');
for ($i = 1; $i <= 5; $i++) {
    fwrite($handle, "Line $i\n");
}
fclose($handle);
?>

A 5

B 1

C 0

D 6

💡 Hint

Count how many times the loop runs and writes a line.

The loop runs 5 times, writing one line each time, so the file will have 5 lines.