js math sum 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: add all elements in array javascript

console.log(
  [1, 2, 3, 4].reduce((a, b) => a + b, 0)
)
console.log(
  [].reduce((a, b) => a + b, 0)
)

Example 3: sum of all numbers in an array javascript

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

Example 4: javascript reduce sum

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

Example 5: summation js

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