//Fibonacci
function fibonacci(n) {
  var array = [0, 1];

  for (var i = 2; i <= n; i++) {
    array.push(array[i - 1] + array[i - 2]);
  }

  return array[n];
}
var n = 6;
var ans = fibonacci(n);
console.log(ans);

function* idMaker() {
    var index = 0;
    while(true)
        yield index++;
}

var gen = idMaker(); // "Generator { }"

console.log(gen.next().value); // 0
console.log(gen.next().value); // 1
console.log(gen.next().value); // 2
// ...

function* fib() {
  var temp, num1 = 0, num2 = 1;
  while (1) {
    yield num1;
    temp = num1;
    num1 = num2;
    num2 += temp;
  }
}
 
// fibonacci generator function
var genFib = fib();
 
// Print the first ten numbers in the fibonacci sequence.
for (var arr = [], i = 0; i < 10; i++) {
  arr.push(genFib.next());
}
alert("1st 10 fibonacci sequence numbers:\n" + arr.join("\n"));