How to filter objects based on whether an array field contains a value?

I have a React app, and I want to filter objects that are in a particular 'category'. On the category object, there is a 'links' field that is an array of Id's. I'm able to get that array and put it into catLinks, below. The objects that I want to filter through are in the json object.

What is confusing me is that the filter I am using does return true when I would expect it (as seen in the console log), but then nothing is returned in the filtered object.

console.log('catLinks: ', catLinks)
// returns 'catLinks: [649d0bae47fa0b4db69f2cf6]'

const filtered = json.filter((l) => {
   catLinks.forEach((catLink) => {
      if(catLink == l._id) {
          console.log(l._id, 'is true')
          // returns '649d0bae47fa0b4db69f2cf6 is true'
          return true
      }
      console.log(l._id, 'is false')
          return false
      })
}).length > 0
console.log('filtered \n', filtered);
// returns 'filtered
//           false'

Can somebody help me figure out what is wrong here?

I have tried using includes() as well as the method above, and can not get it to work.

On javascript, if you want to filter an array you can simply use filter:

const json = [{_id: '649d0bae47fa0b4db69f2cf6'}, {_id: '649d0bae47fa0b4db69f2cf9'}]
const catLinks = ['649d0bae47fa0b4db69f2cf6', '649d0bae47fa0b4db69f2cf7', '649d0bae47fa0b4db69f2cf8']
const filtered = json.filter(x => catLinks.includes(x._id))
console.log(filtered)

to get:

[{_id: "649d0bae47fa0b4db69f2cf6"}]

But if json is a result of a mongodb query, you can get this directly from the query using $in...

For example:

db.collection.find({
  _id: {
    $in: [
      "649d0bae47fa0b4db69f2cf6",
      "649d0bae47fa0b4db69f2cf7",
      "649d0bae47fa0b4db69f2cf8"
    ]
  }
})

See how it works on the playground example

*updated to use includes instead of indexOf, according to a remark by @epascarello