These days i\'m using Slim Framework as my simplest tool to develop the php web api. Using these two articles:
Problem is solved!
My apache is actually normal, and the .htaccess file provided earlier also normal.
The clue is the URL that I used. Previously I used the invalid URL, thus it returned the 404 page error. I just realized it when I Tried to access the newer GET URL via browser with this one;
http://localhost/dev/index.php/getUsers/user1
and now that works!
I just realized it once I found these statements;
If Slim does not find routes with URIs that match the HTTP request URI, Slim will automatically return a 404 Not Found response.
If Slim finds routes with URIs that match the HTTP request URI but not the HTTP request method, Slim will automatically return a 405 Method Not Allowed response with an Allow: header whose value lists HTTP methods that are acceptable for the requested resource.