How can PHP beginners improve their understanding of file handling and data storage to prevent issues like extra characters in user data?

Beginners can improve their understanding of file handling and data storage in PHP by ensuring they are using the correct functions to read and write data, such as `file_get_contents()` and `file_put_contents()`. They should also pay attention to encoding issues that can lead to extra characters in user data, and use functions like `utf8_encode()` and `utf8_decode()` to handle encoding properly.

// Example code snippet to read user data from a file and remove extra characters
$userData = file_get_contents('user_data.txt');
$userData = utf8_encode($userData);
// Process user data here
// Write user data back to the file
file_put_contents('user_data.txt', utf8_decode($userData));