I've created shortcodes that print variable content on the screen. The only way I've been able to get the content to show up is to use return (i.e. return 'Hello World!';). Neither echo nor print works, even for something simple.
Return works to a point, but I can only use it once within the shortcode, which doesn't work if I need to add code between. Is there a way I can use echo or print? Am I missing something?