Javascript how to get length of an object inside an object

Question

I have an object inside an object which and I want to get its length. I tried with Object.keys(obj).length but it shows the length of the parent object I want also to get the length of the child object.

Here's the code I tried.

let data = {
'data': {
  '0x': {
    0: { 
      0: 'test1', 
      330: 'test2'
    }
  }
 }
};

 let hideCtrls = false;
 if(Object.keys(data.data).length == 1){
    let objIn = Object.values(data.data);
    if(Object.values(objIn)[0] == 1) {
      hideCtrls = true;
     } else {
       hideCtrls = false;
     }
  };

console.log(hideCtrls);

I want to check the length of data inside data, if it's length is 1 I want to check the length of the values inside the first object (in this case it is 0x). If the length the child object is also 1 I want to set hideCtrls to true.

I want to get the length of the this last object 0: { 0: 'test1', 330: 'test2' }. Here we have two key value pairs inside so it should return false, if it has only one key value pair it should return true.

NOTE: The keys are dynamic

Answer 1

let data = {
 data: { '0x': { 0: { 0: 'test1', 330: 'test2' } } }
}

function hideCtrls(){
 if(Object.keys(data['data'][Object.keys(data.data)[0]]['0']).length === 1) return true
 else return false
}

console.log(hideCtrls())

Answer 2

Object.values returns an array. If you want the child object, you want to immediately index into it. In general, you can use these two helper functions. You just have to nest enough times to get to the object you care about:

let hasOneChild = (x) => Object.keys(x).length === 1;
let getOnlyChild = (x) => Object.values(x)[0];

let hideCtrls = false;
if(hasOneChild(data.data)){
    let x = getOnlyChild(data.data)
    if(hasOneChild(x)) {
        let y = getOnlyChild(x);
        ...
    } else {
        ...
    }
};

Answer 3

Destructuring at least allows you to avoid the nightmare of a chained, computed accessor string. Here with a helper function for objectLength.

const objectLength = (obj) => Object.keys(obj).length;

const data = { data: { '0x': { 0: { 0: 'test1', 330: 'test2' } } } }

const parent = data.data;
const [{ 0: child }] = Object.values(parent);

const hideCtrls = (objectLength(parent) === 1 && objectLength(child) === 1);

console.log(hideCtrls)