Getting get_nav_menu_locations to work

Hi. I’m new to wordpress and by no means a php expert. (I suppose that’ll be fairly obvious with my questions, but please bear with me.)

For starters I have the following code:

$nav_menu = wp_nav_menu( array( 'theme_location' => 'menu-1','sort_column' => 'menu_order', 'echo' => FALSE ) );

echo $nav_menu;

$locations = get_nav_menu_locations();
echo $locations;

And it’s simply outputting
Array

from
echo $locations;

Obviously my get_nav_menu_locations() function is not working to plan. What am I doing wrong?