How to access dynamic key values in nested objects

Question

This is my JSON file:

{
 "Key": "some-key",
        "some-key": {
        "comLength": 1
        },
}

How do I access the comLength value?

When asking a question it's very important to show us your attempt to solve the problem. Without that it looks like you didn't try and want us to write the code for you. — the Tin Man, Oct 23 '21 at 22:06

score 0 · Answer 1 · answered Oct 23 '21 at 16:30

0

I would do this

parse to custom object
do a For-loop by the required property
break the loop as soon I found the match

answered Oct 23 '21 at 16:30

vargashj

33
6

No reason to iterate – danh Oct 23 '21 at 16:32

score 0 · Answer 2 · answered Oct 23 '21 at 16:32

0

Considering your object variable is named someObject, you can access it like:

var comLength = someObject["some-key"].comLength

Example:

var someObject = {
     "Key": "some-key",
     "some-key": {
        "comLength": 1
     },
}

var comLength = someObject["some-key"].comLength;

console.log(comLength);

answered Oct 23 '21 at 16:32

Ganesh Sanap

1,386
1
8
18

The problem is that I do not know the name of the key – Vazha Kiknadze Oct 23 '21 at 16:35
If you don't know the key, how will you know which property to access from object? – Ganesh Sanap Oct 23 '21 at 16:37

score 0 · Answer 3 · answered Oct 23 '21 at 16:36

You can reference it via the dot notation (.) and the square notation ([]) (the [] notation is mandatory in case of the property key of some-key because of the -)

const obj = {
    "Key": "some-key",
    "some-key": {
            "comLength": 1
        }
};


console.log(obj["some-key"].comLength);
console.log(obj["some-key"]["comLength"]);

score 0 · Answer 4 · answered Oct 23 '21 at 16:49

If you dont know the key but know the property you want inside the key then looping might help

var my_obj = {
  Key: "some-key",
  "some-key": {
    comLength: 1,
  },
};

// the name of the property you want
property = "comLength";

for (item in my_obj) {
  // checks if the the property exists
  if(my_obj[item].hasOwnProperty(property)){ 
    console.log(my_obj[item][property]);
  }
}

Gives output

score 0 · Answer 5 · answered Oct 23 '21 at 19:18

0

const json = {
  "Key": "some-key",
  "some-key": {
    "comLength": 1
  },
}

var key1 = 'some-key';
var key2 = 'comLength';

const value = json[key1][key2];

answered Oct 23 '21 at 19:18

Pramisha C P

319
2
6

1

While this code may answer the question, providing additional context regarding how and/or why it solves the problem would improve the answer's long-term value. You can find more information on how to write good answers in the help center: https://stackoverflow.com/help/how-to-answer . Good luck – nima Oct 23 '21 at 21:45

How to access dynamic key values in nested objects

5 Answers5