Hello,

I’m deep into the javascript challenges now and I keep running into instances in which the suggested solution in the “hint” section use functions that FCC has never gone over.

For example, I came up with the solution below for the “sum all numbers in a range” challenge but its pretty long and inelegant. When I checked the Hints tab, most solutions used Math.min, Math.max, Math.abs and other solutions I haven’t come across yet. Where can I go to learn to learn functions such as these which are not covered by fCC?

```
**Your code so far**
```

```
function sumAll(arr) {
let newArr = arr.sort((a,b) => a-b);
let range = [];
for (let i = newArr[0] + 1; i < newArr[newArr.length-1];i += 1){
range.push(i)
}
let fullArr = newArr.concat(range) ;
let sum = fullArr.reduce((num1, num2) => num1 + num2 ) ;
return sum
}
sumAll([1, 4]);
```

```
**Your browser information:**
```

User Agent is: `Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.45 Safari/537.36`

**Challenge:** Sum All Numbers in a Range

**Link to the challenge:**