如何过滤嵌套的对象数组？

Question

I have an array of objects in which i am trying to filter based on a give condition. The array contains objects with company and products fields.

The filter term is productType: "Timespot" .

I would like to get the company and its products which only has the productType: "Timespot"

const dummyData = [
  {
    companyName: "Company A",
    products: [
      {
        productType: "Variabel pris",
      },
    ],
  },
  {
    companyName: "Company B",
    products: [
      {
        productType: "Fastpris",
      },
      {
        productType: "Fastpris",
      },
      {
        productType: "Fastpris",
      },
      {
        productType: "Timespot",
      },
    ],
  },
  {
    companyName: "Company C",
    products: [
      {
        productType: "Spotpris",
      },
      {
        productType: "Timespot",
      },
    ],
  },
];

const expectedResult = [
  {
    companyName: "Company B",
    products: [
      {
        productType: "Timespot",
      },
    ],
  },
  {
    companyName: "Company C",
    products: [
      {
        productType: "Timespot",
      },
    ],
  },
];

What i am trying:

  dummyData.filter(({ products }) => {
     products.some(product => product.productType === "Timespot")
  });

To provide more context is that i want to get the company and its product which match the given condition.

Answer 1

I think the main problem with your approach is that the filter function will only filter the first array and not the nested one, in order to do what you desire I would use a reduce()

eg

dummyData.reduce((acc,cur)=> { 
    const filteredProducts = cur.products.filter((p)=> p.productType === "Timespot")

    if(filteredProducts.length){
        acc.push({...cur, products:filteredProducts})    
    }
    
    return acc

}, [])

Answer 2

I'd probably do something like this:

function filterProductType(arr, prodType) {
  return arr.filter(obj => obj.products.some(type => type.productType === prodType));
}

console.log(filterProductType(dummyData, "Timespot"));

Returns:

0: companyName: "Company B"
products: Array(4)
  0: {productType: 'Fastpris'}
  1: {productType: 'Fastpris'}
  2: {productType: 'Fastpris'}
  3: {productType: 'Timespot'}
length: 4

1: companyName: "Company C"
products: Array(2)
  0: {productType: 'Spotpris'}
  1: {productType: 'Timespot'}
length: 2

Answer 3

You can use array.filter on the main array, combined with array.find on the nested array of products.

 const dummyData=[{companyName:"Company A",products:[{productType:"Variabel pris"}]},{companyName:"Company B",products:[{productType:"Fastpris"},{productType:"Fastpris"},{productType:"Fastpris"},{productType:"Timespot"}]},{companyName:"Company C",products:[{productType:"Spotpris"},{productType:"Timespot"}]}]; const filtered = dummyData.filter(({products}) => { return products.find(({productType}) => productType === 'Timespot'); }) console.log(filtered)

If you find that you also need to filter by some other productType elsewhere, you could make a more generic function to handle this.

 const dummyData=[{companyName:"Company A",products:[{productType:"Variabel pris"}]},{companyName:"Company B",products:[{productType:"Fastpris"},{productType:"Fastpris"},{productType:"Fastpris"},{productType:"Timespot"}]},{companyName:"Company C",products:[{productType:"Spotpris"},{productType:"Timespot"}]}]; const companyByProductType = ({data, type}) => { return data.filter(({products}) => { return products.find(({productType}) => productType === type); }) } console.log(companyByProductType({data: dummyData, type: 'Timespot'}))