Grasshopper-Summation.js

Summation
Write a program that finds the summation of every number from 1 to num. The number will always be a positive integer greater than 0.

For example:

//summation(2) -> 3
1 + 2

//summation(8) -> 36
1 + 2 + 3 + 4 + 5 + 6 + 7 + 8

var summation = function (num) {
    let result = 0;
    for (var i = 1; i <= num; i++) {
      result += i;
    }
    
    return result;
  } 

or

const summation = n => n * (n + 1) / 2;