Iterating through Nested JavaScript Objects

Iterating through nested JavaScript objects can be challenging, especially when you need to retrieve specific objects based on a property value. Let's consider the following example:

var cars = {
  label: 'Autos',
  subs: [
    {
      label: 'SUVs',
      subs: []
    },
    {
      label: 'Trucks',
      subs: [
        {
          label: '2 Wheel Drive',
          subs: []
        },
        {
          label: '4 Wheel Drive',
          subs: [
            {
              label: 'Ford',
              subs: []
            },
            {
              label: 'Chevrolet',
              subs: []
            }
          ]
        }
      ]
    },
    {
      label: 'Sedan',
      subs: []
    }
  ]
};

If we want to retrieve the object for the "Ford" brand, we can use a recursive approach:

const iterate = (obj, identifier) => {
  for (let key in obj) {
    if (obj[key]['label'] === identifier) {
      return obj[key];
    }
    if (typeof obj[key] === 'object' && obj[key] !== null) {
      const result = iterate(obj[key], identifier);
      if (result) {
        return result;
      }
    }
  }
  return null;
};

const fordObject = iterate(cars, 'Ford');

In this example, the iterate function takes two parameters: the object to search and the identifier string. It iterates through the properties of the object, checking if the label property matches the identifier. If not, it checks if the property is another object and continues the iteration. If no matching object is found, it returns null.