# A Month Of JS

## Jun 3, 2018 · 234 words · 2 minute read

In the past month, I had started and finished three different Frontend Masters courses. I wanted to do something more in-depth and I might follow up with my examples and samples. But, I wanted to publish some of my notes for my own reference and for document of the learning process as well.

The Frontend Masters courses that I took where https://frontendmasters.com/courses/data-structures-algorithms/ , https://frontendmasters.com/courses/javascript-hard-parts/

## Part 1: Data Structures & Algorithms

### Big O

O(n)

O = function n - represents number of elements

O(1) = static amount of time O(log n) - divide and conquer or binary search O(n) directly and linearly with N

O(NlogN) = merge search O(n2) = checking two lists O(infinity) - flipping a coin

Big O is the way we analyze how efficient algorithms (or code in this case) without getting too mired in the details.

O is just absorbing all the other fluff (including the factor on the biggest term.)

If we have no loops and just do something and exit/return, then it’s said we’re doing it in constant time, or **O(1)**.

You can also have **O(log n)** if a code employs a divide-and-conquer strategy (often recursive,) meaning as you add more terms, the increases in time as you add input diminishes.

### Recursion

Recursion is when you define something in terms of itself. When we talk about recursion in computer science, we are talking about a **function that calls itself**.