title: Google Maps V3 - Switching on/off groups of markers
body: <p>I am currently trying to use Google Maps with a bunch of markers on it (extracted from a JSON data file). I want to be able to group the markers in one of two categories and be able to switch them off or on.</p>
  
  <p>I am up to the point where the map is working, the pointers are showing and the switch buttons are flicking on and off - all that is left now is to add the markers to groups and bind the switch buttons to displaying/hiding the markers on the map.</p>
  
  <p>I know that I can use <code>marker.setVisible(false/true)</code> but I'm not sure how or where to use it.</p>
  
  <p>I am new to using Google Maps API v3 so any direction with this would be much appreciated.</p>
  
  <p>I have setup a fiddle with what I have so far, you can see it here: <a href="https://jsfiddle.net/6n25g3n7/4/" rel="nofollow">https://jsfiddle.net/6n25g3n7/4/</a></p>