Filtering array based on another array

December 20, 2022

I am trying to filter arr1, with respect to arr2
what I am trying to achieve is, get all objects of arr1 where it’s corresponding "genre" property in arr2 is "true"

const arr1=[
  {
    "id":1,"genre":["horror","drama","mystery"]
  },
   {
    "id":2,"genre":["romance"]
  },
   {
    "id":3,"genre":["adventure","drama"]
  },
]

const arr2=[
  {
    "genre":"horror",
    "checked":false
  },
  {
    "genre":"drama",
    "checked":true
  },
  {
    "genre":"mystery",
    "checked":false
  },
  {
    "genre":"romance",
    "checked":false
  },
  {
    "genre":"adventure",
    "checked":true
  }
]

so the desired output would be:

[
 {
   "id":1,"genre":["horror","drama","mystery"]
  },
{
    "id":3,"genre":["adventure","drama"]
  },
]

I have tried some configurations the javascript filter methods but i just can’t think of something that works as described. Any help would be appreciated.
Thank you.

>Solution :

This should work.

Use .filter on first array and .some on the other array to determine if it is checked and element of first array contains target genre using .indexOf or even better .includes

const arr1=[
  {
    "id":1,"genre":["horror","drama","mystery"]
  },
   {
    "id":2,"genre":["romance"]
  },
   {
    "id":3,"genre":["adventure","drama"]
  },
]

const arr2=[
  {
    "genre":"horror",
    "checked":false
  },
  {
    "genre":"drama",
    "checked":true
  },
  {
    "genre":"mystery",
    "checked":false
  },
  {
    "genre":"romance",
    "checked":false
  },
  {
    "genre":"adventure",
    "checked":true
  }
]

const result = arr1.filter(a1 => arr2.some(a2 => a2.checked && a1.genre.includes(a2.genre)))
console.log(result)