What are common issues with directory permissions when using PHP to create directories?

Common issues with directory permissions when using PHP to create directories include not having the proper permissions to create directories, leading to errors or directories not being created at all. To solve this, you can set the correct permissions on the parent directory or use PHP's `mkdir` function with the correct permissions parameter.

// Set the correct permissions on the parent directory
chmod('/path/to/parent/directory', 0777);

// Create a directory with the correct permissions
mkdir('/path/to/parent/directory/new_directory', 0777);