add up array elements in javascript code example
Example 1: javascript sum of array
const sum = arr => arr.reduce((a, b) => a + b, 0);
Example 2: summation js
const summation = (n) => (n * (n + 1)) / 2;
const sum = arr => arr.reduce((a, b) => a + b, 0);
const summation = (n) => (n * (n + 1)) / 2;