insertionSort.js

var arr = [5,4,3,2,1]

function insertionSort (arr) {
  if (arr.length === 0) {
    return
  }
	start = 1
  
  while(start <= arr.length-1) {
    var index = start -1
    var val = arr[start]
    while(index >= 0 && arr[index] > val) {
      arr[index + 1] = arr[index]
      index -= 1
    }
    arr[index + 1] = val
    start += 1
  }
}