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filter array of objects by another array of objects

I want to filter array of objects by another array of objects.

I have 2 array of objects like this:

const array = [
    { id: 1, name: 'a1', sub: { id: 6, name: 'a1 sub' } },
    { id: 2, name: 'a2', sub: null },
    { id: 3, name: 'a3', sub: { id: 8, name: 'a3 sub' } },
    { id: 4, name: 'a4', sub: null },
    { id: 5, name: 'a5', sub: { id: 10, name: 'a5 sub' } },
];
const anotherArray = [
    { id: 1, name: 'a1', sub: { id: 6, name: 'a1 sub' } },
    { id: 2, name: 'a2', sub: null },
    { id: 5, name: 'a5', sub: { id: 10, name: 'a5 sub' } },
];

and I want filter array by anotherArray and return items that is not exist in anotherArray and have sub.

So my desired output is:

[ { id: 3, name: 'a3', sub: { id: 8, name: 'a3 sub' } ]

Note: I've done this with for loop but it work too slow. I want to do this with using Arrays filter method

Code I have with for loop:

for (let i = 0; i < array.length; i += 1) {
    let exist = false;
    const item = array[i];
    for (let j = 0; j < anotherArray.length; j += 1) {
      const anotherItem = anotherArray[j];
      if (item.id === anotherItem.id) {
        exist = true;
      }
    }
    if (item.sub && !exist) {
      this.newArray.push({
        text: `${item.sub.name} / ${item.name}`,
        value: item.id,
      });
    }
  }
like image 341
arif Avatar asked Dec 03 '18 22:12

arif


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1 Answers

Like Felix mentioned, Array#filter won't work faster than native for loop, however if you really want it as functional way, here's one possible solution:

const array = [
    { id: 1, name: 'a1', sub: { id: 6, name: 'a1 sub' } },
    { id: 2, name: 'a2', sub: null },
    { id: 3, name: 'a3', sub: { id: 8, name: 'a3 sub' } },
    { id: 4, name: 'a4', sub: null },
    { id: 5, name: 'a5', sub: { id: 10, name: 'a5 sub' } },
];

const anotherArray = [
    { id: 1, name: 'a1', sub: { id: 6, name: 'a1 sub' } },
    { id: 2, name: 'a2', sub: null },
    { id: 5, name: 'a5', sub: { id: 10, name: 'a5 sub' } },
];

const r = array.filter((elem) => !anotherArray.find(({ id }) => elem.id === id) && elem.sub);

console.log(r);
like image 101
kind user Avatar answered Sep 19 '22 10:09

kind user