Google Maps Zoom To Fit All Markers

datFitBounds.js

// create an array of coordinates to zoom on
var latlng = [{
  name: "South West Marker",
  latlng: new google.maps.LatLng(swLat, swLng)
}, {
  name: "North East Marker",
  latlng: new google.maps.LatLng(neLat, neLng)
}];
var latlngbounds = new google.maps.LatLngBounds();
  for (var i = 0; i < latlng.length; i++) {
    latlngbounds.extend(latlng[i].latlng);
  }
// zoom on coordinates
map.fitBounds(latlngbounds);