js get name of parent key in an object

Question

I have an object and I want one of the values to be the name of the parent key:

{
   name: 'Jon',
   address: {
        city: 'Vienna',
        parent: <How can I dynamically set this to 'address'>
   }
}

Answer 1

well i cant understand from your question if you handle nested objects with more then 1 level but this code will work for the first level. if you want unlimited levels you need to do it with recursion

const obj = {
   name: 'Jon',
   address: {
        city: 'Vienna'
   }
}

for(let i in obj){
 if(typeof obj[i] === 'object'){
     obj[i].parent = i;
    }
}
console.log(obj)

Answer 2

We can achieve this by making a recursive function which recursively updates all the levels inside the object and child objects with the parent property. Here is a recursive function which will work for n-levels.

var obj = {
   name: 'Jon',
   address: {
        city: 'Vienna',
        pincode :{
          val : 110,
          Area : {
            val : "xyz"
          }
        },
   },
   designation : {
      post : "Manager",
      salary : {
         value : "100"
      }
   }
}

function updateParent(obj,parent){
  if(parent)
    obj.parent = parent;
  for(var key in obj){
    if(obj[key].constructor.toString().indexOf("Object") >= 0){
        updateParent(obj[key],key);
    }
  }
}
updateParent(obj);
console.log(obj);

Answer 3

The approach I took was to make the object iterable then use a for...of to search for the desired child property and change the value to it's parent object's name:

var data = {
  name: 'Jon',
  address: {
    city: 'Vienna',
    parent: '<How can I dynamically set this to \'address\'>'
  }
};

data[Symbol.iterator] = function() {
  var i = 0;
  var keys = Object.keys(this);
  return {
    next: function() {
      var value = keys[i],
        done = false;
      i++;

      if (i > keys.length) {
        done = true;
      }

      return {
        value,
        done
      }
    }
  }
}

function setChildProperty(parentPropertyName, childPropertyName) {
  for (prop of data) {
    if (prop == parentPropertyName) {
      data[prop][childPropertyName] = prop;
    }
  }
}

//Before
console.log(data);
setChildProperty("address", "parent")
//After
console.log(data);