Google Map , zoom to bound

zoom_all.js

// map: an instance of google.maps.Map object
// latlng: an array of google.maps.LatLng objects
// latlng: needs lat, long as interger , so must parse them to interger first.
var latlngbounds = new google.maps.LatLngBounds();
for (var i = 0; i < latlng.length; i++) {
  latlngbounds.extend(latlng[i]);
}
map.fitBounds(latlngbounds);