Sum range of int's in List<int>

c#, list, sum

Solution

You can accomplish this by using `Take` & `Sum`:

var list = new List<int>()
{
    1, 2, 3, 4
};

// 1 + 2 + 3
int sum = list.Take(3).Sum(); // Result: 6

If you want to sum a range beginning elsewhere, you can use `Skip`:

var list = new List<int>()
{
    1, 2, 3, 4
};

// 3 + 4
int sum = list.Skip(2).Take(2).Sum(); // Result: 7

Or, reorder your list using `OrderBy` or `OrderByDescending` and then sum:

var list = new List<int>()
{
    1, 2, 3, 4
};

// 3 + 4
int sum = list.OrderByDescending(x => x).Take(2).Sum(); // Result: 7

As you can see, there are a number of ways to accomplish this task (or related tasks). See `Take`, `Sum`, `Skip`, `OrderBy` & `OrderByDescending` documentation for further information.

Problem

I reckon this will be quite trivial but I can't work out how to do it. I have a `List<int>` and I want to sum a range of the numbers. Say my list is: ``` var list = new List<int>() { 1, 2, 3, 4 }; ``` How would I get the sum of the first 3 objects? The result being 6. I tried using `Enumerable.Range` but couldn't get it to work, not sure if that's the best way of going about it. Without doing: ``` int sum = list[0] + list[1] + list[2]; ```

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