If marker.setMap == null do something

Question

I want to implement something by Google maps and I need to know if setMap is alreay set or is null. How can I implement something like this:

if (marker.setMap == null)
{
    marker.setMap(map);
}

Answer 1

You have to call the getMap function, not check if the setMap function is null. This will toggle the marker:

if (marker.getMap() == null) marker.setMap(map);
else marker.setMap(null);

or even

if (!marker.getMap()) marker.setMap(map);
else marker.setMap(null);