First algorithm challenge

function sumAll(arr) {
var newArr = [];
var big = Math.max(arr[0],arr[1]);
var small = Math.min(arr[0],arr[1]);

for (var i = small; i<arr.length;i++){
if(i < big){

for (var j = big; i<arr.length;i++){
if(j > small){


for (var n = small; n<arr.length; n++){
if(n !== arr[i]) {
return newArr.reduce(function(a, b){
return a+b;


sumAll([1, 4]);

So, with this function, I am getting what I am supposed to with 1, 4.
and 4, 1. When I try to plug in 5, 10, and 10, 5, though, it doesnt
even run the for loop.

In other words I don’t think it’s running the for loop unless “small” is one. If it is bigger it won’t seem to compute!

I’m copying my replay to your other thread here (with slight edits).

You’re very close. In fact, you’ve already written too much. Think about the first loop

for (var i = small; i < arr.length; i++) {
        if (i < big) {

I believe your idea is to start the loop at the lower number, then add all the numbers between small and big, exclusive. I assume that because it makes sense, but there’s a problem. For an array of size 2, this will only run twice. When small and big only have two numbers in between them, like [1,4], that works fine. When the numbers are farther apart, like [5,10], it adds two numbers and then quits out. Your code almost works, though. Here are some hints:

  • Freebie - get rid of the if clause in your loop.
  • Think about why you had the if clause there in the first place. It’s not a bad idea, but where in the loop declaration would it be more useful?
  • You’ll have to make one more slight change to the loop declaration to get it to work. What’s the first number your loop will add to the array?
  • Do the other two for loops do anything for you? What will the outcome of the first loop be?strong text