Why doesn’t my .inc file return $output? [on hold]

On my .module page, I have the following code:

/**  * Implements hook_init().  */ function sky_view_init() {     drupal_add_css(drupal_get_path('module', 'sky_view') . '/css/sky_view.css');     module_load_include('inc', 'sky_view', 'includes/db_process');     hello_world(); } 

In my inc file, I have the following:

<?php  function hello_world(){     $  output = [];     $  output['#prefix'] = '<p>99999999999999999999999999999999999999</p>';     dpm("hello world function has ran...");     return $  output; } 

When I run the code, I get the dpm hello world function has ran, but the return $ output does not display on screen. So I know the function is running, but why isn’t it returning my output? I have other functions in my .module page with a $ output return and they work just fine, but doing the same thing in my inc file, it does not work. Why is this?