我正在嘗試刪除反應中的筆記，但我收到一個錯誤，您無法在初始化之前訪問新筆記？

Question

React Find error in delete note function that can't access the newNotes before初始化那為什么不能刪除該注釋？

deleteNote function 正在工作，因為它的控制台使用我在其中寫入的 id 記錄消息但它沒有刪除便箋，我已經聲明了 newNote 並在其中初始化了值但我不明白為什么它給出了錯誤?

    const [notes, setNotes] = useState(notesInitial) 
    //Add Note
    const addNote = (title, description, tag) => {
        //TODO API CALL
        console.log("adding a new note");
        const note = {
            "_id": "63074e71318fac99be7ce65a",
            "user": "62ee8f0b86e5c4946d3b75d5",
            "title": title,
            "description": description,
            "tag": tag,
            "date": "2022-08-25T10:26:57.324Z",
            "__v": 0
        };
        setNotes(notes.concat(note));
    }



    //Delete A Note
    const deleteNote = (id) => {

        console.log("The node delteing with id" + id);
        I think I missing something here
        const newNotes = newNotes.filter((notes) => { return notes._id !== id })
        setNotes(newNotes);
    }




    return (
        <noteContext.Provider value={{ notes, addNote, deleteNote, editNote }}>
            {props.children}
        </noteContext.Provider>
    )

}


export default NoteState;

Answer 1

const newNotes = newNotes.filter((notes) => { return notes._id !== id })

newNotes再次被聲明，它不會從您的useState中獲取。 在deleteNode function 中將其命名為其他任何名稱。

const deleteNote = (id) => {

        console.log("The node delteing with id" + id);
        I think I missing something here
        const newNotes2 = notes.filter((notes) => { return notes._id !== id })
        setNotes(newNotes2);
    }

Answer 2

是的，您在這里犯了錯誤，因此將其轉換為

 //Delete A Note
    const deleteNote = (id) => {

        console.log("The node delteing with id" + id);
        I think I missing something here
        const newNotes = newNotes.filter((notes) => { return notes._id !== id })
        setNotes(newNotes);
    }

至

const deleteNote = (id) => {

        console.log("The node delteing with id" + id);
        I think I missing something here
        const newNotes = notes.filter((note) => { return note._id !== id })
        setNotes(newNotes);
    }