filter array of objects based on a key

Question

I have two array of objects as below:

1st array:

const arr1 = [
  {
    name: 'Jackson',
    email: 'jack@email.com',
    _id: '634793ba0d09e246dbed7988'
  },
  {
    name: 'Carlson',
    email: 'carl@email.com',
    _id: '633c33880d09e246dbed6e3f'
  }
]

2nd array:

const arr2 = [
  {
    name: 'Samson',
    email: 'sam@gmail.com',
    _id: '"634e878db465120ccc6ca81f'
  },
  {
    name: 'Jennifer',
    email: 'jenny@abc.com',
    _id: '633c339c0d09e246dbed6eeb'
  },
  {
    name: 'Carlson',
    email: 'carl@email.com',
    _id: '633c33880d09e246dbed6e3f'
  }
]

Now, I want to filter my 2nd array based on the _id. If same ids, then remove that object from the array.

Expected result should be:

[
  {
    name: 'Samson',
    email: 'sam@gmail.com',
    _id: '"634e878db465120ccc6ca81f'
  },
  {
    name: 'Jennifer',
    email: 'jenny@abc.com',
    _id: '633c339c0d09e246dbed6eeb'
  }
]

Below is my approach:

this.finalArray = this.arr2.filter(item => {
  this.arr1.forEach(other=> {
    if (item._id !== other._id) {
      return item;
    }
  });
});

But I'm getting an empty array. How can I achieve that?

this can be done without nested loop `const set1 = new Set(); arr1.forEach(elem=>set1.add(elem._id)); const filterArr = arr2.reduce((acc,curr)=>{ if(!set1.has(curr._id)){ acc.push(curr) } return acc; },[]); console.log(filterArr)` — brk, Oct 18 '22 at 12:54

score 1 · Answer 1 · answered Oct 18 '22 at 12:49

const arr1 = [
  {
    name: 'Jackson',
    email: 'jack@email.com',
    _id: '634793ba0d09e246dbed7988'
  },
  {
    name: 'Carlson',
    email: 'carl@email.com',
    _id: '633c33880d09e246dbed6e3f'
  }
]

const arr2 = [
  {
    name: 'Samson',
    email: 'sam@gmail.com',
    _id: '"634e878db465120ccc6ca81f'
  },
  {
    name: 'Jennifer',
    email: 'jenny@abc.com',
    _id: '633c339c0d09e246dbed6eeb'
  },
  {
    name: 'Carlson',
    email: 'carl@email.com',
    _id: '633c33880d09e246dbed6e3f'
  }
]

const result = arr2.filter(item => !arr1.find(obj => obj._id === item._id));
console.log(result)

filter array of objects based on a key

1 Answers1