How to wait for function to finish before continuning in Node.js

Question

I am trying to create a route in Node.js/Express that reads data from two queries and then increments a count based on that data from the queires. Since Node.js is asynchro

Answer 1

Embrace asynchronicity:

var express = require('express');
var router = express.Router();


var total = 0;

/* GET home page. */
router.get('/', function(req, res, next) {
  increment(3, function() {                 // <=== Use callbacks
      increment(2, function() {
          console.log(total);
          res.end();
      });
  });
});



var increment = function(n, callback){    // <=== Accept callback
    //Wait for n seconds before incrementing total n times
    setTimeout(function(){
        for(i = 0; i < n; i++){
            total++;
        }   
        callback();                        // <=== Call callback
    }, n *1000);
};
module.exports = router;

Or use a promises library, or use events. In the end, they're all asynchronous callback mechanisms with slightly different semantics.