I have a nested array like this:

array = [
    {
        "id": "67",
        "sub": [
            {
                "id": "663",
            },
            {
                "id": "435",
            }
        ]
    },
    {
        "id": "546",
        "sub": [
            {
                "id": "23",
                "sub": [
                 {
                     "id": "4",
                 }
             ]
            },
            {
                "id": "71"
            }
        ]
    }
]

I need to find 1 nested object by its id and get all its parents, producing an array of ids.

find.array("71")
=> ["546", "71"]

find.array("4")
=> ["546", "23", "4"]

What's the cleanest way to do this? Thanks.

I have a nested array like this:

array = [
    {
        "id": "67",
        "sub": [
            {
                "id": "663",
            },
            {
                "id": "435",
            }
        ]
    },
    {
        "id": "546",
        "sub": [
            {
                "id": "23",
                "sub": [
                 {
                     "id": "4",
                 }
             ]
            },
            {
                "id": "71"
            }
        ]
    }
]

I need to find 1 nested object by its id and get all its parents, producing an array of ids.

find.array("71")
=> ["546", "71"]

find.array("4")
=> ["546", "23", "4"]

What's the cleanest way to do this? Thanks.

• javascript
• jquery
• search
• nested

• Can the same Id appear in your structure more than once? – Paul Commented Sep 11, 2011 at 21:24
• Use recursion to walk down the tree and build the parent list each iteration. – user166390 Commented Sep 11, 2011 at 21:25
• What's your goal with this type of data-structure? It feels like you're going to have to loop through everything to get what you want. – rwilliams Commented Sep 11, 2011 at 21:25
• @rwilliams nested categories. – Harry Commented Sep 11, 2011 at 21:29

2 Answers 2

Recursively:

function find(array, id) {
  if (typeof array != 'undefined') {
    for (var i = 0; i < array.length; i++) {
      if (array[i].id == id) return [id];
      var a = find(array[i].sub, id);
      if (a != null) {
        a.unshift(array[i].id);
        return a;
      }
    }
  }
  return null;
}

Usage:

var result = find(array, 4);

Demo: http://jsfiddle/Guffa/VBJqf/

Perhaps this - jsonselect.

EDIT: I've just had a play with JSONSelect and I don't think it's appropriate for your needs, as JSON does not have an intrinsic 'parent' property like xml.

It can find the object with the matching id, but you can't navigate upwards from that. E.g.

JSONSelect.match(':has(:root > .id:val("4"))', array)

returns me:

[Object { id="4"}]

which is good, it's just that I can't go anywhere from there!