Big O notation

Overview

• Describe how closely a finite series approximates a given function

• Analyzing algorithms for efficiency in computer science

f(n) = O(g(x)) f(n) <= c * (g(n))

Notation	Name
O(1)	constant
O(N)	linear
O(N^2)	quadratic

// O(1)
function getFirstIndex(list) {
  return list[0];
}

// O(n)
function iterator(list) {
  for (var i = 0; i < list.length; i++) {
    // do something
  } 
}

// O(n^2)
function iterator(list) {
 for (var i = 0; i < list.length; i++) {
   for (var j = 0; j < list2.length; j++) {
     // do something
   }
 }
}

Reference

https://en.wikipedia.org/wiki/Big_O_notation