how to find sum of an array javascript code example

Example 1: array sum javascript

const arr = [1, 2, 3, 4];
const sum = arr.reduce((a, b) => a + b, 0);
// sum = 10

Example 2: sum of all elements in array javascript

arrSum = function(arr){  return arr.reduce(function(a,b){    return a + b  }, 0);}