I have two arrays, i want to push some items from arr1 to arr2 preventing duplicates because i've already added some items to arr2 that are also in arr1. i am doing this in react js 

```
                arr1.forEach(q1 => {
                    arr2.forEach(q2 => {
                        if (q1.lessonId !== q2.lessonId) {
                            if (q2.obtainedMarks >= q2.passingMarks) {
                                User.findByIdAndUpdate(req.body.userId, { $push: { arr1: { $each: 
                                    [q2._id] } } }, (err, doc) => {

                                })
                            }
                        }
                    })
                });

```