mongodb count.js

count.js

var mongo = require('mongodb').MongoClient;
var age = process.argv[2];

var url = 'mongodb://localhost:27017/learnyoumongo';

mongo.connect(url, function(err, db){
  if(err) throw err;
  var parrots = db.collection('parrots');
  parrots.count({
    age: {
      $gt: +age
    }
  }, function(err, count){
    if (err) throw err;
    console.log(count);
    db.close();
  });
})