Check if two arrays contain identical ids

May 17, 2023

By default, I have arrays with the name of the continents.

europe= [];
northAmerica = [];
southAmerica = [];
asia = [];

And i have two arrays with some data

arr1 = [1,3];

arr2 = [
  { country: "Brazil", id: 1, continent: "southAmerica" },
  { country: "Germany", id: 2, continent: "europe" },
  { country: "India", id: 3, continent: "asia" },
  { country: "China", id: 4, continent: "asia" },
];

If the id matches in the arrays, I need to send the string obj.country to the corresponding array of the continent.

I tried like this:

arr2.map((item) => {
        if (arr1.find((id) => id === item.id)) {
          if (item.continent === "southAmerica") {
            southAmerica.push(item.country);
          }
          if (item.continent === "asia") {
            asia.push(item.country);
          }
        }
      });

But only the last value is sent to the arrays.

>Solution :

Do it like this.

const continents = {
  europe: [],
  northAmerica: [],
  southAmerica: [],
  asia: []
};


arr1 = [1, 3];

arr2 = [
  { country: "Brazil", id: 1, continent: "southAmerica" },
  { country: "Germany", id: 2, continent: "europe" },
  { country: "India", id: 3, continent: "asia" },
  { country: "China", id: 4, continent: "asia" },
];

arr1.forEach(_id => {
  arr2.find(obj => {
    if (obj.id === _id) {
      continents[obj.continent].push(obj.country);
      return;
    }
  });
});

console.log(continents);