sum of function in js code example

Example 1: sum javascript

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

Example 2: sum function in javascript

let sum = (...para) => para.reduce((d,b) => d + b);