how to add up all numbers of an array in javascript code example

Example 1: sum of all numbers in an array javascript

const arrSum = arr => arr.reduce((a,b) => a + b, 0)

Example 2: Write a function that takes an array of number values and returns the sum.

function amountTotal(amount) {
        var total = 0;
        for (i = 0; i < amount.length; ++i) {
             total += amount[i]; // add each element in an array to total
        }
        return total;// return sum of elements in array
}