add up all the values in an array javascript code example

Example 1: total array with function

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

Example 2: how to add up all numbers in an array

var numbers = [10, 20, 30, 40] 
var sum = 0;
for (var i = 0; i < numbers.length; i++) {  sum += numbers[i]}

Example 3: sum all elements in array javascript

arr.reduce((a, b) => a + b)

Example 4: how to add up all numbers in an array

const numbers = [10, 20, 30, 40] 
add = (a, b) =>  a + b
const sum = numbers.reduce(add)