Get way of the search in json structure in javascript

Question

I have a json structure that comes from a relational database of tables: countries->states->cities, the json object has this format:

var object = {
    'countries': [
        {
            'id_country': 1,
            'name': 'Country 1',
            'states': [
                {
                    'id_state': 1,
                    'name': 'State 1',
                    'cities': [
                        {
                            'id_city': 1,
                            'name': 'City 1'
                        },
                        {
                            'id_city': 2,
                            'name': 'City 2'
                        }
                    ]
                },
                {
                    'id_state': 2,
                    'name': 'State 2',
                    'cities': [
                        {
                            'id_city': 3,
                            'name': 'City 3'
                        }
                    ]
                }
            ]
        }
    ]
};

Making use of a function with parameters similar to this one:

var arrays = ['countries', 'states', 'cities'];
var keySearch = 'id_city';
var valueSearch = 3;

function getPath(object, arrays, keySearch, valueSearch);

I want to return an array like this:

var result = [0, 1, 0];

The first element of the result corresponds to the position of the country, the second of the state and the third of the city. How can I do this in javascript? I've tried to do it with a recursive method following similar examples but I haven't been able to make it work. Thanks in advance.

Answer 1

Very basically, fyi,

// get the first country of the object.
console.log(object.countries[0]);

// get the second state of the first country of the object.
console.log(object.countries[0].states[1]);

// get the first city of the first state of the first country of the object. 
console.log(object.countries[0].states[0].cities[0]);

Answer 2

You could take a recursive approach and store the path as an object reference for each nested call.

function getPath(object, [array, ...arrays], key, value, path = []) {
    object[array].some((o, i) => {
        if (
            o[key] === value ||
            arrays.length && path.length < getPath(o, arrays, key, value, path).length
        ) return path.unshift(i);
    });
    return path;
}

var object = { countries: [{ id_country: 1, name: 'Country 1', states: [{ id_state: 1, name: 'State 1', cities: [{ id_city: 1, name: 'City 1' }, { id_city: 2, name: 'City 2' }] }, { id_state: 2, name: 'State 2', cities: [{ id_city: 3, name: 'City 3' }] }] }] };
            
console.log(getPath(object, ['countries', 'states', 'cities'], 'id_city', 3));
console.log(getPath(object, ['countries', 'states', 'cities'], 'id_city', 7));

.as-console-wrapper { max-height: 100% !important; top: 0; }