title: java beginner- is an arraylist call by reference
body: <p>In a java program, I want 3 arraylist variables to be modified by a call to a single function.</p>
  
  <p>Am I correct in thinking that if I pass these 3 arraylists as parameters to that function, then all 3 can be modified within the function? Or will I have to modify each arraylist in a separate function, and specify that array list as the return value, to ensure that it is modified.</p>