按 ID javascript 合并数组中的对象

Question

So I am trying to merge 2 arrays of objects by ID-s ( ID and AUTOMOBIL ) with this code I only push last array of objects(OPREMA) . Someone have any idea how can I get all of them in the spot they should be?

So when ID in a1 is == 1 I need all of OPREMA in a2 witch AUTOMOBIL is equal to 1 to save it together it a1 , but with this code it's only saving last one.

 const a1 = [ { ID: "2", TIP: "A3", VRSTA: "Limousine", $$hashKey: "object:3" }, { ID: "1", TIP: "A5", VRSTA: "Coupe", $$hashKey: "object:7" }, ]; const a2 = [ { AUTOMOBIL: "1", OPREMA: { ID: "5", NAZIV_OPREME: "Automatski", VRSTA_OPREME: "2", CIJENA: "15000", OPIS: "Automatski mjenjač", }, }, { AUTOMOBIL: "1", OPREMA: { ID: "3", NAZIV_OPREME: "Benzin", VRSTA_OPREME: "1", CIJENA: "7000", OPIS: "Gorivo benzin", }, }, { AUTOMOBIL: "1", OPREMA: { ID: "19", NAZIV_OPREME: "1.0", VRSTA_OPREME: "5", CIJENA: "7000", OPIS: "potrosnja 3-6l", }, }, { AUTOMOBIL: "1", OPREMA: { ID: "11", NAZIV_OPREME: "Sportback", VRSTA_OPREME: "3", CIJENA: "70000", OPIS: "sportski izgled šasije", }, }, { AUTOMOBIL: "1", OPREMA: { ID: "8", NAZIV_OPREME: "Quattro", VRSTA_OPREME: "4", CIJENA: "15000", OPIS: "Pogon na sve kotače", }, }, ]; const a3 = a1.map(t1 => ({...t1, ...a2.find(t2 => t2.AUTOMOBIL === t1.ID) })); //RESULT OF a3 console.log(a3);

Answer 1

In your question you never specified how exactly you want the elements of a2 to be saved in the a1 element. I'm assuming that you need them as a array under the OPREMA property. Your code was pretty close but instead of find you needed to use filter to keep all elements that match.

const a3 = a1.map(t1 => {
      const matchingElements = a2.filter(t2 => t2.AUTOMOBIL === t1.ID);
      return ({...t1, OPREMA: matchingElements.map(({ OPREMA }) => OPREMA) });
});