Saving multiple documents with Mongoose and doing something when last one is saved

A useful library to coordinate asynchronous operations is async. In your case, the code would look something like this:

var people = [ person1, person2, person3, person4, ... ];async.eachSeries(people, function(person, asyncdone) {  person.save(asyncdone);}, function(err) {  if (err) return console.log(err);  done(); // or `done(err)` if you want the pass the error up});

Using promises and Array.map()

const userPromises = persons.map(user => {  return new Promise((resolve, reject) => {    person.save((error, result) => {      if (error) {        reject(error)      }      resolve(result);    })  })});Promise.all(userPromises).then((results) => {  //yay!  //results = [first, second, etc...]}, (error) => {  //nay!})

I would recommend to have an array and save with iteration. Will have same performance but code would be cleaner.

You can have

var Person = mongoose.model('Person');var people = [];people[0] = new Person({id: 'someid'});people[0].set('name', 'Mario');people[1] = new Person({id: 'someid'});people[1].set('name', 'Mario');people[2] = new Person({id: 'someid'});people[2].set('name', 'Mario');var errors = [];for(person in people){ people[person].save(function(err, done){  if(err) errors.push(err);  if (person === people.length){ yourCallbackFunction(errors){    if (errors.length!=0) console.log(errors);    //yourcode here   };  } });}