Iterate till the end of the nested objects in javascript

Question

I have a nested object like this :

let obj = {
_id: {},
person: {
    $search: {
        lname: true
    },
    _id: {},
    fname: {},
    something:{
        $search: {
            fname: true
        },
    }
},
code: {},
$search: {
    mname: true
},
vnvEmpName: {}
}

I have to retrieve all the keys inside the $search key, even if the object contains multiple occurences of $search it should return all the keys inside it which is :

lname 
fname
mname

I tried this :

function search(obj, id) {
var result = "";
// iterate the object using for..in

    for (var keys in obj) {
        // check if the object has any property by that name
        if (obj.hasOwnProperty(keys) && typeof obj[keys] === 'object') {
            // if the key is not undefined get it's value
            if (obj[keys][id] !== undefined) {
                result = (obj[keys][id])
            } else {
                // else again call the same function using the new obj value
                console.log("reahced")
                search(obj[keys], id)
            }
        }

    }
    return result;

}
console.log(search(obj, '$search'))

But I am getting only the key( lname ) which is under the first instance of the $search . Please help me out to iterate it till the end.

Answer 1

You could check if the key is $search and take that nested key or check the nested objects.

 function getSearch(object, key) { return Object.entries(object).reduce((r, [k, v]) => r.concat( k === key ? Object.keys(v)[0] : v && typeof v === 'object' ? getSearch(v, key) : [] ), []); } var object = { _id: {}, person: { $search: { lname: true }, _id: {}, fname: {}, something: { $search: { fname: true } } }, code: {}, $search: { mname: true }, vnvEmpName: {} }; console.log(getSearch(object, '$search'));

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

Answer 2

You can create an iterator function using generators and then use it for your purpose. Here is an example code:

 let obj = { _id: {}, person: { $search: { lname: true }, _id: {}, fname: {}, something: { $search: { fname: true } } }, code: {}, $search: { mname: true }, vnvEmpName: {} }; //iterator function function* iterate(obj, stack='') { for (let property in obj) { if (obj.hasOwnProperty(property)) { if (typeof obj[property] == "object") { yield *iterate(obj[property], stack + '.' + property); } else { yield [stack, property, obj[property]]; } } } } //using iterator function for searching let searchkey = "$search" for (let value of iterate(obj)) { if(value[0].indexOf(searchkey) !== -1) console.log(value); }

I hope it helps.

Answer 3

You can try this

 let obj = { _id: {}, person: { $search : { lname: true }, _id: {}, fname: 'test', something:{ $search: { fname: true }, } }, code: {}, $search: { mname: true }, vnvEmpName: {} } var result; function search(obj, id) { // iterate the object using for..in for (var key in obj) { if (obj.hasOwnProperty(key)) { if (obj[key][id] !== undefined) { result = (obj[key][id]); return result; } else { // else again call the same function using the new obj value console.log("reahced") search(obj[key], id) } } } return result; } console.log(search(obj, 'lname'))