getSum.js

/*
Given two integers a and b, which can be positive or negative, find the sum of all the integers between and including them and return it. If the two numbers are equal return a or b.

Note: a and b are not ordered!

Examples (a, b) --> output (explanation)
(1, 0) --> 1 (1 + 0 = 1)
(1, 2) --> 3 (1 + 2 = 3)
(0, 1) --> 1 (0 + 1 = 1)
(1, 1) --> 1 (1 since both are same)
(-1, 0) --> -1 (-1 + 0 = -1)
(-1, 2) --> 2 (-1 + 0 + 1 + 2 = 2)
Your function should only return a number, not the explanation about how you get that number.
*/

function getSum(a, b){
    let arr = []; //Array to store numbers between a & b

    let min = Math.min(a,b)
    let max = Math.max(a,b)
    //Minimum and Maximum numbers between a & b

    for(let i = min; i <= max; i++ ){
        arr.push(i)
    } //Loop to 

    return arr.reduce((acc, cumm) => acc + cumm, 0)
}

console.log(getSum(1,0));