MongoDB on Node.js doesn't work, it returns undefined -

in following code:

var mongoclient = require('mongodb').mongoclient; mongoclient.connect('mongodb://localhost:27017/db_name', function(err, db){     if (err) throw err;      var collection = db.collection('col_name');     console.log(collection.find().toarray(function(err, items){}));  }); 

when run above, doesn't return results , instead returns undefined. missing?

also, in order confirm there exist collections on db, there are, tried add console.log(db.getcollectionnames());, looks has no such method in node.js driver. still possible confirm existence of collections? (anyway want use debug in these situations - don't need method though).

thanks.

don't log entire find() function, checking in callback:

collection.find().toarray(function(err, items){     console.log(items); });