Big O 4th Rule

// Log all pairs of array i.e. [1,1], [1,2] [1,3] [2,1] [2,2] etc
const boxes = [1,2,3,4,5];

function logArrayPairs(array) {
    for (let i = 0; i < array.length; i++) {
      for (let j = 0; j < array.length; j++) {
          console.log(array[i], array[j])
      }
    }
}

logArrayPairs(boxes);

// O(n) * O(n) = O(n^2) : Quadratic times
// nested is multiplied