Sending results of MongoDB find() using Express - node.js

Question

I am new to NodeJS and I am trying to connect to MongoDB I prepared a query and I can see the output on server by traversing the cursor. But I want to send the output of find() to response.
var cursor = db.collection('dbLocations').find(
{$and: [
{type: locationType},
{createdAt : { "$gte": new Date(createdAt), "$lt": date1 }}
]}).skip(skip).limit(count);
Now I am getting error like
Cannot set headers after they are sent to the client if I do a string concate and then JSON.stringify
I tried pretty() but it gives me error skip(...).limit(...).toString(...).pretty is not a function
or skip(...).limit(...).pretty is not a function.
I am totally unable to figure out how to convert as I am not clear about the concept of callback() and all solutions have that. Is there a simple stringify, parse or pretty kind of solution to it.
Below is my express snippet for get, it looks very messy right now. I want to send the find() output instead of random stuff.
app.get('/api/first', function(request, response) {
response.writeHead(200, {'Content-Type': 'application/json'});
var locationType = request.body.type;
var createdAt = request.body.createdAt;
//var pageNumber = parseInt(request.body.pageNumber);
console.log(locationType);
console.log(createdAt);
//console.log(pageNumber);
var date1 = new Date(createdAt);
date1.setDate(date1.getDate() + 1);
var count = 2;
var str="";
var skip;
if(request.body.pageNumber)
skip = parseInt((request.body.pageNumber-1)*count);
else
skip = 0;
MongoClient.connect(url, function(err, client) {
if (err) throw err;
console.log('Connected');
var db = client.db('locationapi');
var cursor = db.collection('dbLocations').find(
{$and: [
{type: locationType},
{createdAt : {"$gte": new Date(createdAt), "$lt": date1}}
]}
).skip(skip).limit(count);
cursor.each(function(err, doc) {
if(err) throw err;
if(doc !== null) {
console.log(doc); str=str+doc;
} else client.close();
});
client.close();
});
var myObj = {
name: 'jgj',
job: 'Ninja'
}; // random stuff
response.end(JSON.stringify(myObj));
});

Answer 1

db.collection('dbLocations').find({
$and: [{
type: locationType
}, {
createdAt: {
"$gte": new Date(createdAt),
"$lt": date1
}
}]
}, {
skip: skip,
limit: count
}).toArray(function (err, docs) {
if (err) return res.status(500).send({error: err})
res.send(docs)
});
https://mongodb.github.io/node-mongodb-native/3.3/api/Collection.html#find
https://mongodb.github.io/node-mongodb-native/3.3/api/Cursor.html#toArray