How to iterate through nested Objects and combine key and value?

May 6, 2022

const products = {
  value: {
    phone: [],
    lamp: [],
    car: ["bmw", "toyota", "audi"]
  }
};

In the given object I want to iterate and get keys.
Note that values are array of strings.

I’d like to get all keys and if values are not empty arrays I want to combine with keys and return an array with this structure

   [
    phone,
    lamp,
    car-bmw,
    car-toyota,
    car-audi
  ]

Here is what I did so far, which is not what I want

const products = {
  value: {
    phone: [],
    lamp: [],
    car: ["bmw", "toyota", "audi"]
  }
};

const mappedProducts = Object.entries(products.value).map(([value, items]) => {
  //console.log("value :", value, "items :", items)
  if (items.length > 0) {
    return {
      car: items.map((c) => c)
    };
  }
});

console.log(mappedProducts);

Any help will be appreciated.

>Solution :

I modified what you did a bit, you can you flatMap

const products = {
  value: {
    phone: [],
    lamp: [],
    car: ["bmw", "toyota", "audi"]
  }
};

const mappedProducts = Object.entries(products.value).flatMap(([value, items]) => {
  //console.log("value :", value, "items :", items)
  if (items.length > 0) {
    return items.map(item => `${value}-${item}`);
  } else {
    return [value];
  }
});

console.log(mappedProducts);