您将如何比较两个数组并在两个数组之间进行过滤？

Question

So my first state sortedFavorites:

This is my second state watchedFilter:

So sortedFavorites state contains everything watchedFilter state contains, what I want to do is that compare the two arrays and filter out everything which both sortedFavorites and watchedFilter have in common. So I don't want any of the movies in watchedFilter to be in sortedFavorites.

For example: sortedFavorites= {1,2,3,4,5} watchedFilter={1,2,3} The result I desire is: sortedFavorites={4,5}

This is what I tried but it doesn't do anything:

filterFavorites = () => {
    let showFavorites = this.state.sortedFavorites.filter(fav => !this.state.watchedFilter.includes(fav))
    this.setState(state => ({
        ...state,
        ...{ sortedFavorites: showFavorites }
    }));
}

Answer 1

You could create a new array with all entries from sortedFavorites that are not in watchedFilter .

Since there are separate objects in both arrays includes will not work, because that will check for exact object references . You can check if the id is the same instead:

filterFavorites = () => {
  this.setState(previousState => {
    const sortedFavorites = previousState.sortedFavorites.filter(
      fav => !previousState.watchedFilter.some(w => w.id === fav.id)
    );

    return { sortedFavorites };
  });
}