compare two arrays and take values ​from the first array not contained in the second array

Question

I have this array with 3 of size

[
  'decdbaf8-db89-4d4b-973a-e8edab55927c',
  'c553c2f7-eff6-476e-b718-2814a7fa5435',
  '8717092f-5820-474b-9dd9-165e2649180f'
]

and this array with size equals 2:

[
  {
    id: 'c553c2f7-eff6-476e-b718-2814a7fa5435',
    name: 'test',
    codReference: '15422aa',
    category_id: '7a026a80-f3d2-462a-ad5d-598e9eabf693',
    created_at: 2020-10-29T22:23:35.928Z,
    updated_at: 2020-10-29T22:23:35.928Z,
    deleted_at: null
  },
  {
    id: 'decdbaf8-db89-4d4b-973a-e8edab55927c',
    name: 'test',
    codReference: '2',
    category_id: '7a026a80-f3d2-462a-ad5d-598e9eabf693',
    created_at: 2020-10-29T22:23:37.784Z,
    updated_at: 2020-10-29T22:23:37.784Z,
    deleted_at: null
  }
]

I know that if I were to get only one item that is not contained in the array, I would just use: indexOf (value)> -1;

but how can I compare the two arrays and get only the values ​​of the first array that are not contained in the second array

Answer 1

Something like this perhaps (combination of filter and some)

 const first = [ 'decdbaf8-db89-4d4b-973a-e8edab55927c', 'c553c2f7-eff6-476e-b718-2814a7fa5435', '8717092f-5820-474b-9dd9-165e2649180f' ]; const second = [{ id: 'c553c2f7-eff6-476e-b718-2814a7fa5435', name: 'test', codReference: '15422aa', category_id: '7a026a80-f3d2-462a-ad5d-598e9eabf693', deleted_at: null }, { id: 'decdbaf8-db89-4d4b-973a-e8edab55927c', name: 'test', codReference: '2', category_id: '7a026a80-f3d2-462a-ad5d-598e9eabf693', deleted_at: null } ] const result = first.filter(x => !second.some(y => y.id === x)); console.log(result)

Answer 2

You could use a filter. Here's a working solution:

 var arr1 = [ 'decdbaf8-db89-4d4b-973a-e8edab55927c', 'c553c2f7-eff6-476e-b718-2814a7fa5435', '8717092f-5820-474b-9dd9-165e2649180f' ] var arr2 = [ { id: 'c553c2f7-eff6-476e-b718-2814a7fa5435', name: 'test', codReference: '15422aa', category_id: '7a026a80-f3d2-462a-ad5d-598e9eabf693', created_at: '2020-10-29T22:23:35.928Z', updated_at: '2020-10-29T22:23:35.928Z', deleted_at: null }, { id: 'decdbaf8-db89-4d4b-973a-e8edab55927c', name: 'test', codReference: '2', category_id: '7a026a80-f3d2-462a-ad5d-598e9eabf693', created_at: '2020-10-29T22:23:37.784Z', updated_at: '2020-10-29T22:23:37.784Z', deleted_at: null } ] var arr = arr2.map(_ => _.id); var res = arr1.filter( function(n) { return !this.has(n) }, new Set(arr) ); console.log(res);