**Tell us what’s happening:**

Well, I don’t understand how working method sort()

**Your code so far**

```
function sumAll(arr) {
arr = arr.sort()
let sum = arr[0] + arr[1]
for(let i = arr[0] + 1; i < arr[1]; i++ ) {
sum += i
}
return sum
}
sumAll(5, 10) // Why it's return unsorted array? because of this loop not working
```

method sort() sorting array and return a sorted array, but not correct for me. If I pass in method 5 and 10 - method not sorting array, but if i pass 5 and 9 - it’s sorted - why? I already solve this problem, but it took me

сhange the sorting mechanism:

```
arr.sort((a, b) => a < b ? 0 : 1)
```

**Your browser information:**

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.

**Link to the challenge:**

https://learn.freecodecamp.org/javascript-algorithms-and-data-structures/intermediate-algorithm-scripting/sum-all-numbers-in-a-range