Fast fibonacci in nodejs using caching

fib.js

/* in routes/fib.js */

var cache = new Array();

function fib(n) {

  if(n.toString() in cache)
    return cache[n.toString()];

  if(n < 2) { return 1; }
  else { 
    var fibB = fib(n - 2) + fib(n - 1);
    cache[n.toString()] = fibB;
    return fibB;
  }
}

exports.getFib = function(req, res) {
  console.log(req.params);

  var n = req.params.num;

  console.log('Calculate fibonacci for ' + n);

  console.time('fib');
  var result = fib(n);
  console.timeEnd('fib');

  res.jsonp(result);
}

index.js

var fib = require('./fib');

/**
 * Set up routes
 */

module.exports = function(app, options) {
  
  app.get('/fib/:num', fib.getFib);

};