Create an Object from dot notation

By Oleksandr Klymovych

This was puzzling me all afternoon, and I came up with a bloody terrible work-around using eval, this evening I decided to do a little more research and found this answer on StackOverflow.

I've adapted it and it seems to work a treat:

(() => {

  const obj = {}

  const expand = (output, mystr, value) => {
    const items = mystr.split(".") // split on dot notation
    let ref = output // keep a reference of the new object
    //  loop through all nodes, except the last one
    for (let i = 0; i < items.length - 1; i++) {
      if (!ref[items[i]]) {
        // create a new element inside the reference
        ref[items[i]] = {}
      }
      ref = ref[items[i]] // shift the reference to the newly created object 
    }
    ref[items[items.length - 1]] = value // apply the final value
    return output // return the full object
  }

  const arr = [
    "thingOne.thingTwo.thingThree",
    "thingOne.thingTwo.thingFour",
    "thingyOne.thingyTwo.thingyThree",
    "thingyOne.thingyTwo.thingyFour"
  ]

  arr.forEach(a => {
    expand(obj, a, true)
  })
  
  console.log(obj)

})()

I was nearly there on my tod TBH, but wussed out at the end, thisis lovely though! It produces this lovely object:

{
  "thingOne": {
    "thingTwo": {
      "thingThree": true,
      "thingFour": true
    }
  },
  "thingyOne": {
    "thingyTwo": {
      "thingyThree": true,
      "thingyFour": true
    }
  }
}