Deep clone

deep-clone.js

function deepClone(obj) {
  if (Array.isArray(obj))
    return obj.map((el) => deepClone(el))

  if (
    typeof obj !== 'object' ||
    Object.prototype.toString.call(obj) !== '[object Object]' ||
    obj === null
  )
    return obj

  let clone = {}
  for (let i in obj)
    if (obj.hasOwnProperty(i))
    	clone[i] = deepClone(obj[i])

  return clone
}