Dropping all databases in MongoDB

Just used mongorestore for database transfer to another server and noticed that resulting database have more records. I may assume mongorestore does not delete existing data. Hence after googling a bit I've found a way to clear all databases first and then didn't have any problems with restore.

So here's the recipe how to drop all databases in MongoDB:

var dbs = db.getMongo().getDBNames()
for(var i in dbs){
    db = db.getMongo().getDB( dbs[i] );
    print( "dropping db " + db.getName() );
    db.dropDatabase();
}

References:
http://stackoverflow.com/questions/6376436/mongodb-drop-every-database