How can PHP constants like __FILE__ help in resolving file path issues?

When dealing with file path issues in PHP, using constants like __FILE__ can help provide a reliable and consistent way to reference the current file's path. This can be especially useful when including files from different directories or when moving code between environments with different directory structures. By using __FILE__ as a reference point, you can ensure that file paths are always resolved correctly regardless of the context in which the code is executed.

// Example usage of __FILE__ constant to resolve file path
$currentFilePath = __FILE__;
$includedFilePath = dirname($currentFilePath) . '/included_file.php';
include $includedFilePath;