Recursion: An important intermediate level concept for nested processing

recursion-simple.js

// Recursion: a function may call itself and work with the return value.
// It can do this multiple times before returning the original execution

const getDeepTotal = function deepTotal(inputArray) {
  let total = 0
  inputArray.forEach((el)=>{
    total += Array.isArray(el) ? deepTotal(el) : el
  })
  return total
} 

console.log(getDeepTotal([1, 2, [1, 2, 3], 2, 3]))
// >> 14

// Recursion may cause endless
// loops, so do check inputs