custom array flat

by Saksham Malhotra

JavaScript

let arr = [1, [2, 3, [4]],
  [5, 6]
]

function flatMap(arr) {
  let newArr = []
  for (let val of arr) {
    if (val instanceof Array) {
      newArr.push.apply(newArr, flatMap(val))
    } else {
      newArr.push(val)
    }
  }
  return newArr
}

console.log(flatMap(arr))