Filter unique objects from any array - Javascript

element
April 5, 2023
282 views
1 vote
2 Answers

I have an array of objects in javascript, I am creating a new array from it but only with some properties. What I need is to filter the unique objects and eliminate the repeated ones, I’m trying to do it in the same function but I don’t know if it’s possible

This is the array:

let filters = [
  {
     "model":"audi",
     "year":2012,
     "country":"spain"
  },
  {
    "model":"bmw",
    "year":2013,
    "country":"italy"
  },
  {
    "model":"audi",
    "year":2020,
    "country":"spain"
  }
]

This is the function:

function filterObject(data: any) {
  let result = data.map((item: any) => {
    return {
      hub: {
        country: item.country,
        model: item.model
      }
    }
  })
  return result

}

This is what I get:

[
   {
      "hub":{
         "country":"spain",
         "model":"audi"
      }
   },
   {
      "hub":{
         "country":"italy",
         "model":"bmw"
      }
   },
   {
      "hub":{
         "country":"spain",
         "model":"audi"
      }
   }
]

This is what I need:

[
   {
      "hub":{
         "country":"spain",
         "model":"audi"
      }
   },
   {
      "hub":{
         "country":"italy",
         "model":"bmw"
      }
   }
]

Answers

Try this updated function

function filterObject(data: any) {
  let hubs: {[key: string]: any} = {};

  data.forEach((item: any) => {
    const key = `${item.country}-${item.model}`;

    if (!hubs[key] || item.year > hubs[key].year) {
      hubs[key] = { country: item.country, model: item.model, year: item.year };
    }
  });

  let result = Object.values(hubs).map((hub) => {
    return { hub: { country: hub.country, model: hub.model } };
  });

  return result;
}

itz working as per your expectation.

You can use Map to ensure only unique items:

function filterObject(data:any) {
  const uniqueObjects:any = [];
  const uniqueMap = new Map();

  data.forEach((item:any) => {
    const key = item.model + item.country;
    if (!uniqueMap.has(key)) {
      uniqueMap.set(key, true);
      uniqueObjects.push({
        hub: {
          country: item.country,
          model: item.model
        }
      });
    }
  });

  return uniqueObjects;
}

Playground

Please signup or login to give your own answer.

Click here to cancel reply.

Filter unique objects from any array – Javascript

Answers