what is the Fibonacci Sequence

The Fibonacci Sequence is a series of numbers.

The sequence looks like this

0, 1, 1, 2, 3, 5, 8, 13, 21, 34…

To find the next number in the Fibonacci Sequence you will have to find the sum of the two numbers before it.

To get the 4th number you will have to add 1 and 2 because 1 is the second number and 2 is the third number.

0, 1, 1, 2, 3

a way to to implement using JavaScript

A way to implement the Fibonacci Sequence is using a for loop that loops to the position you want to find.


function fibonacciSequence (position) {
  // starting point
  let array = [0, 1];

  for (let i = 2; i <= position; i++){
    // add the previous two value of the fibonacci sequence and push it into the array
    array.push(arr[i - 2] + arr[i -1]);

  // return the number in the array at the position passed into the function
  return array[position];

The function takes in a number and returns the number in the Fibonacci Sequence in that position.

The function creates an array that holds the Fibonacci Sequence by repeatedly adding the last two numbers in the array.

It will repeat until the array includes the index of, position, which is passed to the function as an argument.

The position passed into the function is used to return a element from the array.


fibonacciSequence(4); // 3


This spiral can be made with the Fibonacci Sequence.

fibonacci sequence spiral
what is a factorial

Factorial can be used to find out how many ways to order a set of things. it looks like this 7!.

what is localStorage

localStorage allows you to store and access strings in your browser.