Question

I have to create several markers on Google Maps, in run-time.

Their initial position is randomly defined.

When they are created, how can I change position of some of them? New position is also randomly defined.

I did tried with

marker1.setPosition(pt);

… but, I’m getting error

marker1 is not defined

I guess that problem is that marker1 is not defined in moment when map is created… Something like that.

Can you help me how can I solve this one?

p.s. There is no limit of how many markers will be created.

UPDATE Markers are created with:

function addNewMarker( locationsTotal ) {

if (document.getElementById("lon1").value == '') document.getElementById("lon1").value = '19';
if (document.getElementById("lat1").value == '') document.getElementById("lat1").value = '45';

var parliament = (map.getCenter());

var newMarker = 'marker' + locationsTotal;
newMarker = new google.maps.Marker({
  name:newMarker,
  id:newMarker,
  map:map,
  draggable:true,
  animation: google.maps.Animation.DROP,
  position: parliament, 
  icon: 'img/pin.png'
});

google.maps.event.addListener(newMarker, "dragend", function() {
  var center = newMarker.getPosition();
  var latitude = center.lat();
  var longitude = center.lng();
  var newLon = 'lon' + locationsTotal;
  var newLat = 'lat' + locationsTotal;
  document.getElementById(newLon).value = longitude;
  document.getElementById(newLat).value = latitude;
});

}

Answer 1

As You can see newMarker is visible only in the scope of addNewMarker function.
What you need is to store your markers in array visible in global scope.
For example:
Modify your function:

var allMarkers = [];
function addNewMarker( locationsTotal ) {
   //.... skip
  allMarkers.push(newMarker);
}

All your markers are now stored in an array so you can manipulate them.

To access marker by name add function:

function getMarker(name) {
  for (k in allMarkers)
     if (allMarkers[k].name == name) return allMarkers[k];
  return null;
}