What are some common pitfalls beginners face when trying to set chmod permissions in PHP?

Common pitfalls beginners face when setting chmod permissions in PHP include not understanding the octal representation of permissions, not using the correct file path, and not checking if the file exists before setting permissions. To solve these issues, make sure to convert the desired permissions to octal format (e.g., 0644 for read and write permissions for owner and read permissions for others), provide the correct file path, and use the `file_exists()` function to check if the file exists before setting permissions.

// Example of setting chmod permissions in PHP
$filePath = 'path/to/file.txt';
$permissions = 0644;

if (file_exists($filePath)) {
    chmod($filePath, $permissions);
    echo "Permissions set successfully.";
} else {
    echo "File does not exist.";
}