How to get nested parent path from a JSON tree in JavaScript?

Question

I have a JSON tree structure like this.

[
    {
      "title":"News",
      "id":"news"
    },
    {
      "title":"Links",
      "id":"links",
      "children":[
        {
          "title":"World",
          "id":"world",
          "children":[
            {
              "title":"USA",
              "id":"usa",
              "children":[
                {
                  "title":"Northeast",
                  "id":"northeast"
                },
                {
                  "title":"Midwest",
                  "id":"midwest"
                }                
              ]
            },
            {
              "title":"Europe",
              "id":"europe"
            }
          ]
        }
      ]
    }
  ]

What i want is when i pass "northeast" to a function() it should return me the dot notation string path from the root. Expected return string from the function in this case would be "links.world.usa.northeast"

nested parent path? you'll need to explain what *you* mean by that — Jaromanda X, Jan 13 '20 at 08:58
Objects are not aware of their "parents", since objects don't have a parent. You've to mark the parent as a property in the objects having a "parent". — Teemu, Jan 13 '20 at 09:00
Please add the code you've tried. There are many similar questions: [Get parent and grandparent keys from a value inside a deep nested object](https://stackoverflow.com/q/57711141) and [Javascript - Find path to object reference in nested object](https://stackoverflow.com/q/43636000) and [Find a full object path to a given value with JavaScript](https://stackoverflow.com/q/53543303) — adiga, Jan 13 '20 at 09:05

score 13 · Accepted Answer · answered Jan 13 '20 at 09:19

You could test each nested array and if found, take the id from every level as path.

const pathTo = (array, target) => {
    var result;
    array.some(({ id, children = [] }) => {
        if (id === target) return result = id;
        var temp = pathTo(children, target)
        if (temp) return result = id + '.' + temp;
    });
    return result;
};

var data = [{ title: "News", id: "news" }, { title: "Links", id: "links", children: [{ title: "World", id: "world", children: [{ title: "USA", id: "usa", children: [{ title: "Northeast", id: "northeast" }, { title: "Midwest", id: "midwest" }] }, { title: "Europe", id: "europe" }] }] }];

console.log(pathTo(data, 'northeast'));

How to get nested parent path from a JSON tree in JavaScript?

1 Answers1