how to filter duplicate strings in an array

I have a response from an API that comes in this style

"0": {
  "id": 78,
  "fotos": ["78.0", null, null, null, null, null],
  "status": "A",
  "marcaJ": { "id": 12, "marca": "ROYAL CANIN" },
  "item_linkWeb": {
    "id": 98,
    "emp_id": 1,
    "item_id": 78,
    "linkWeb_id": 72,
    "updated_at": "2021-10-07T18:35:14.000000Z",
    "ecommerce_id": 1662526,
    "coresJ": [
      { "ecommerce_id": null, "cor": null, "hex": null },
      { "ecommerce_id": null, "cor": null, "hex": null }
    ],
    "atributosJ": {
      "Peso": { "valor": "null" },
      "Tamanho": { "valor": "null" }
    },
    "fotosJ": [6354862],
    "linkWeb": {
      "id": 72,
      "titulo": "Ra\u00e7\u00e3o Royal Canin Mini Adulto 2,5 kg"
    }
  },
  "estoque": null,
  "tabela": {
    "itemTabela_id": 4,
    "item_id": 78,
    "vVenda": 136.9,
    "vPromo": null,
    "vPromoData": null
  }
},
"1": {
  "id": 209,
  "fotos": ["209.0", null, null, null, null, null],
  "status": "A",
  "marcaJ": { "id": 12, "marca": "ROYAL CANIN" },
  "item_linkWeb": {
    "id": 114,
    "emp_id": 1,
    "item_id": 209,
    "linkWeb_id": 88,
    "updated_at": "2022-03-28T15:02:28.000000Z",
    "ecommerce_id": 1662563,
    "coresJ": [
      { "ecommerce_id": null, "cor": null, "hex": null },
      { "ecommerce_id": null, "cor": null, "hex": null }
    ],
    "atributosJ": {
      "Peso": { "valor": "2,5 kg" },
      "Tamanho": { "valor": "null" }
    },
    "fotosJ": [6355016],
    "linkWeb": {
      "id": 88,
      "titulo": "Ra\u00e7\u00e3o Royal Canin Mini Indoor Junior 2,5 kg"
    }
  },
  "estoque": { "item_id": 209, "estAtual": 3 },
  "tabela": {
    "itemTabela_id": 4,
    "item_id": 209,
    "vVenda": 159.9,
    "vPromo": null,
    "vPromoData": null
  }
},

I tried to make a filter of when marcaJ.marca is repeated returns only one value

      <div *ngFor="let categ of filtro" class="form-check">
    <input  (change)="filterMarcas($event)" class="form-check-input" type="radio"  name="marca" value={{categ.marcaJ.marca}} id="flexCheckChecked" >
    <label class="form-check-label" for="flexCheckChecked">
      {{categ.marcaJ.marca}}
    </label>
  </div>


            this.filtro.push(resB[i]);
            this.filtro = this.filtro.filter( (ele,pos)=>this.filtro.indexOf(ele) == pos);

but did not return the expected value, it seems that I am not able to access themarcaJ.marca in the filter

>Solution :

Are you looking to turn that array from 2 entries into one? You can do something like this:

const result = this.filtro.filter((record, index) => temp.findIndex(check => check.marcaJ.marca === record.marcaJ.marca) === index);

This finds the first occurrence of each marca