deepclone.js

const deepClone = obj => {
  const clone = {}
  for (let i in obj) {
    if (obj[i] != null && typeof obj[i] === 'object') {
      clone[i] = deepClone(obj[i])
    } else {
      clone[i] = obj[i]
    }
  }
  return clone
}

const a = {
  a: 'a',
  b: {
    b: 'b'
  }
}

const c1 = deepClone(a)
c1.a = '1'
c1.b.b = '2'

console.log(c1, a)