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.

mname as well. Sorry missed it. – ra_pri May 17 '18 at 11:19 — ra_pri, May 17 '18 at 11:19

score 0 · Answer 1 · edited Feb 18 '21 at 21:43

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'));

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score 0 · Answer 2 · edited Feb 18 '21 at 21:43

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.

score 0 · Answer 3 · edited Feb 18 '21 at 21:43

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'))

Iterate till the end of the nested objects in javascript

3 Answers3