How can PHP developers ensure that directory indexes are properly set up to avoid errors like "File does not exist"?

To ensure that directory indexes are properly set up to avoid errors like "File does not exist," PHP developers can use the `file_exists()` function to check if a file exists before attempting to access it. This helps prevent errors by verifying the existence of the file before performing any operations on it.

$file_path = 'path/to/file.txt';

if (file_exists($file_path)) {
    // File exists, proceed with operations
    $file_contents = file_get_contents($file_path);
    echo $file_contents;
} else {
    // File does not exist, handle error
    echo "File does not exist.";
}