如何从本地存储阵列中删除唯一项？ （到目前为止没有任何效果）

Question

I am totally stuck.

I am working on the Library project from The Odin Project's JavaScript course, and I am trying to use localStorage so that the user can save their "library" to, well, their local storage.

I've never been able to 100% successfully use localStorage before. It seems simple enough, but for some reason, there was some kind of block in my brain about how to utilize it correctly. This time, however, I was able to get my program to be able to 1) save the user's data (via a button click), 2) load it correctly into the individual "cards" on the page, and 3) delete the entire storage (via another button click). I am extremely excited about this... it feels so good to not know how to do something and then get it to work.

The one thing that has me totally confused is being able to delete a unique item from the localStorage array. When you click the "New Book" button on my page, a modal comes up, and you're required to enter a book's title, author, # of pages, and whether or not you have read it. There's also an option to set the background color. Clicking Submit will then generate a "card" with the book's information on it.

Each card has an X button in the corner. When the X button is clicked, the card is deleted from the page. I want it so that it (meaning that card's book's object) is also deleted from the local storage array (preferably without the user having to press the "Save to local storage" button again, although it isn't a dealbreaker).

Each time the user creates a new book, the book's details are saved as an object into an array called libraryBooks (which I then stringify so I can use localStorage). From my understanding, in order to be able to delete individual parts of the array, I need to use code that is something like this:

libraryBooks.splice(libraryBooks.indexOf(item), 1);

I think my issue is that I don't know how to get the item's index number. I'm not sure how to make it so that the program follows the instructions "When this X button is clicked, find that book's object in the array" if that makes sense. At this point, I've tried several things, and I'm just totally confused.

So yeah. Any help would be wonderful. I've gone through and commented my code to try to help clarify what everything does, I've included the entire thing so that I don't potentially leave something important out related to my problem. and so that it works in the code snippet, But in case it doesn't: here are links to the code repo and the live demo:

• Live demo
• Code repo

 // Link DOM elements const newBookBtn = document.querySelector('.newbook'); // New Book button const showBooks = document.querySelector('.show-books'); // div container const cardClose = document.querySelectorAll('.cardclose'); // button to close card const openEls = document.querySelectorAll("[data-open]"); // for popup boxes const closeEls = document.querySelectorAll("[data-close]"); // for popup boxes const submitBtn = document.querySelector('.submitbtn'); // Submit button (in popup boxes) const formBoxes = document.querySelectorAll('.form-box'); // Form box within popup box const formRadio1 = document.querySelector('#bookreadyes'); // Form radio buttons within popup box const isVisible = "is-visible"; // for popup boxes const colorDropdown = document.querySelector('select'); // Color-picking dropdown in popup boxes let libraryBooks = []; // localstorage buttons (save and delete) const saveStorage = document.getElementById('save-storage'); const deleteStorage = document.getElementById('delete-storage'); // Button event listeners saveStorage.addEventListener('click', updateLocalStorage); deleteStorage.addEventListener('click', deleteLocalStorage); submitBtn.addEventListener('click', addBookToLibrary); // If the 'books' key is empty, simply set libraryBooks to empty array. if (localStorage.getItem('books') === null) { libraryBooks = []; // Otherwise, set library books array to get items from the 'books' key } else { const booksFromStorage = JSON.parse(localStorage.getItem('books')); libraryBooks = booksFromStorage; } // The Book constructor function Book(title, author, pages, read) { this.title = title this.author = author this.pages = pages this.read = read this.info = function() { return `${this.title} by ${this.author}, ${this.pages} pages, ${read}`; } } // Add book to library function. function addBookToLibrary() { let bookTitle = document.querySelector('#book-title'); let bookAuthor = document.querySelector('#book-author'); let bookPages = document.querySelector('#book-pages'); let bookReadYes = document.querySelector('#bookreadyes') let bookReadNo = document.querySelector('#bookreadno'); let alertWords = document.querySelector('.alertwords'); // Alert if form elements are empty let bookRead; if (bookReadYes.checked) { bookRead = 'Read'; } else if (bookReadNo.checked) { bookRead = 'Not read'; } // Creating a new book object via the Book constructor let newBook = new Book(bookTitle.value, bookAuthor.value, bookPages.value, bookRead); // If any form elements are empty, throw error and don't submit book. If none of them are empty, proceed. if (bookTitle.value.length === 0 || bookAuthor.value.length === 0 || bookPages.value.length === 0) { alertWords.textContent = 'Please fill in all fields.'; } else { alertWords.textContent = ''; document.querySelector('.modal.is-visible').classList.remove(isVisible); // Closes the modal formBoxes.forEach(formBox => { formBox.value = ""; // Sets the form values so they're blank the next time the New Book button is pressed }); formRadio1.checked = true; // Set the radio buttons so that the "Yes" button is automatically selected (otherwise, the user's last choice will be selected) // Push the new book object into libraryBooks array libraryBooks.push(newBook); // The rest of the lines of code in this function create the actual book card on page const newCard = document.createElement('div'); const newCardTitle = document.createElement('h4'); const newCardAuthor = document.createElement('p'); const newCardPages = document.createElement('p'); const newCardRead = document.createElement('span'); newCardTitle.setAttribute('class', 'title-style'); newCardAuthor.setAttribute('class', 'author-style'); newCardPages.setAttribute('class', 'pages-style'); newCardRead.setAttribute('class', 'read-style'); newCard.classList.add('isVisible', 'cardbox', colorPicker()); showBooks.appendChild(newCard); for (let i = 0; i < libraryBooks.length; i++) { newCardTitle.innerHTML = `${libraryBooks[i].title}`; let closeBtn = "<button type='button' class='close-default' onclick='$(this).parent().parent().remove();'>x</button>"; newCardTitle.innerHTML += closeBtn; newCardAuthor.innerHTML = `by ${libraryBooks[i].author}`; newCardPages.innerHTML = `<strong>Pages</strong>: ${libraryBooks[i].pages}`; newCardRead.innerHTML = `<strong>Status</strong>: ${libraryBooks[i].read}`; } newCard.appendChild(newCardTitle); newCard.appendChild(newCardAuthor); newCard.appendChild(newCardPages); newCard.appendChild(newCardRead); } } // Stuff for popup capability for (const el of openEls) { el.addEventListener("click", function() { const modalId = this.dataset.open; document.getElementById(modalId).classList.add(isVisible); }); } for (const el of closeEls) { el.addEventListener("click", function() { this.parentElement.parentElement.parentElement.classList.remove(isVisible); }); } document.addEventListener("click", e => { if (e.target == document.querySelector(".modal.is-visible")) { document.querySelector(".modal.is-visible").classList.remove(isVisible); } }); // Keyboard shortvut for modal: ESC key to close document.addEventListener("keyup", e => { // if we press the ESC if (e.key == "Escape" && document.querySelector(".modal.is-visible")) { document.querySelector(".modal.is-visible").classList.remove(isVisible); } }); cardClose.forEach(card => { card.addEventListener('click', function() { this.parentNode.parentNode.removeChild(this.parentNode.parentNode); return false; }); }) // Switch function for setting the background color of the book's card function colorPicker() { switch (colorDropdown.value) { case 'red': return 'cardback-red'; break; case 'orange': return 'cardback-orange'; break; case 'yellow': return 'cardback-yellow'; break; case 'green': return 'cardback-green'; break; case 'blue': return 'cardback-blue'; break; case 'purple': return 'cardback-purple'; break; case 'dark': return 'cardback-dark'; break; case 'grey': return 'cardback-grey'; break; default: return 'cardback-white'; break; } } // Update local storage function updateLocalStorage() { localStorage.setItem('books', JSON.stringify(libraryBooks)); } // Delete local storage function deleteLocalStorage() { window.localStorage.clear(); showBooks.textContent = ""; } // Get localStorage data and set it to the variable "data" const data = JSON.parse(localStorage.getItem('books')); // Load the saved local storage objects into cards (almost identical to addBookToLibrary()) function loadLocalStorage(array, book) { let bookTitle; let bookAuthor; let bookPages; let bookRead; for (let i = 0; i < array.length; i++) { bookTitle = book.title; bookAuthor = book.author; bookPages = book.pages; bookRead = book.read; } // Create book card on page const newCard = document.createElement('div'); const newCardTitle = document.createElement('h4'); const newCardAuthor = document.createElement('p'); const newCardPages = document.createElement('p'); const newCardRead = document.createElement('span'); newCardTitle.setAttribute('class', 'title-style'); newCardAuthor.setAttribute('class', 'author-style'); newCardPages.setAttribute('class', 'pages-style'); newCardRead.setAttribute('class', 'read-style'); newCard.classList.add('isVisible', 'cardbox', colorPicker()); showBooks.appendChild(newCard); for (let i = 0; i < array.length; i++) { newCardTitle.innerHTML = `${bookTitle}`; let closeBtn = "<button type='button' class='close-default' onclick='$(this).parent().parent().remove();'>x</button>"; newCardTitle.innerHTML += closeBtn; newCardAuthor.innerHTML = `by ${bookAuthor}`; newCardPages.innerHTML = `<strong>Pages</strong>: ${bookPages}`; newCardRead.innerHTML = `<strong>Status</strong>: ${bookRead}`; } newCard.appendChild(newCardTitle); newCard.appendChild(newCardAuthor); newCard.appendChild(newCardPages); newCard.appendChild(newCardRead); } // Required in order to load saved books onto page for (let i = 0; i < data.length; i++) { loadLocalStorage(data, data[i]); }

 * { margin: 0; padding: 0; } body, html { display: flex; align-items: center; flex-direction: column; background-color: #cedee9; height: 100vh; padding: 10px; font-family: 'Rubik', sans-serif; } body { max-height: 100%; } input { padding: 5px; } label { margin-bottom: 5px; margin-top: 10px; font-size: .9rem; } input[type='text'] { font-size: .75rem; font-family: 'Poppins', sans-serif; }.radio-option1 { margin-right: 5px; } h4 { display: flex; justify-content: space-between; align-items: center; font-size: 1.2rem; }.close { background: none; font-size: 1.5rem; border: 0; margin-left: 10px; transition: 0.5s ease; }.close:hover { cursor: pointer; color: rgb(58, 84, 140); }.submitbtn { border: 1px solid rgb(58, 84, 140); color: white; background-color: rgb(58, 84, 140); padding: 8px 20px; margin: 0 auto; width: 100%; border-radius: 5px; transition: 0.5s ease; }.submitbtn:hover { cursor: pointer; background-color: rgb(40, 54, 85); border-color: rgb(40, 54, 85); }.book-form { display: flex; flex-direction: column; width: 200px; } /* Testing this comment */ input { margin-bottom: 10px; } p { margin-top: 5px; }.bookcard { width: 200px; display: flex; justify-content: flex-start; flex-direction: column; }.cardbox { background-color: white; width: 250px; margin: 10px; padding: 12px 20px 20px 20px; box-shadow: rgba(60, 64, 67, 0.3) 0px 1px 2px 0px, rgba(60, 64, 67, 0.15) 0px 2px 6px 2px; }.alertwords { color: #df0a0a; }.show-books { display: flex; flex-wrap: wrap; }.title-style { margin-bottom: -5px; }.author-style { font-size: .9rem; margin-bottom: 20px; }.pages-style, .read-style { font-size: .9rem; } option { font-family: 'Poppins', sans-serif; font-size: .8rem; } select { padding: 5px; font-family: 'Poppins', sans-serif; font-size: .8rem; } #option-red, .cardback-red { background-color: rgb(241, 191, 191); } #option-orange, .cardback-orange { background-color: #ffcb9a; } #option-yellow, .cardback-yellow { background-color: #fffda1; } #option-green, .cardback-green { background-color: #9cd6af; } #option-blue, .cardback-blue { background-color: #a1d3f0; } #option-purple, .cardback-purple { background-color: #e6c1ff; } #option-grey, .cardback-grey { background-color: #cfcfcf; } #option-dark, .cardback-dark { background-color: #282f52; color: white; } /* RESET RULES –––––––––––––––––––––––––––––––––––––––––––––––––– */ * { padding: 0; margin: 0; } a { color: inherit; text-decoration: none; }.close-modal { cursor: pointer; background: transparent; border: none; outline: none; font-size: inherit; }.btn-group { text-align: center; }.open-modal { font-weight: bold; background: steelblue; color: white; padding: 0.75rem 1.75rem; margin-bottom: 1rem; border-radius: 5px; border: 0; transition: 0.5s ease; }.open-modal:hover { background-color: rgb(40, 54, 85); cursor: pointer; }.open-modal:active { background-color: rgb(40, 54, 85); }.open-modal:focus { background-color: rgb(40, 54, 85); } /* MODAL –––––––––––––––––––––––––––––––––––––––––––––––––– */.modal { position: fixed; top: 0; left: 0; right: 0; bottom: 0; display: flex; align-items: center; justify-content: center; padding: 1rem; background: rgba(0, 0, 0, 0.781); cursor: pointer; visibility: hidden; opacity: 0; transition: all 0.35s ease-in; }.modal.is-visible { visibility: visible; opacity: 1; }.modal-dialog { position: relative; max-width: 800px; max-height: 80vh; border-radius: 5px; background: white; overflow: auto; cursor: default; }.modal-dialog>* { padding: 1rem; }.modal-header, .modal-footer { font-weight: 700; background: #a8c0f2; }.modal-header { display: flex; align-items: center; justify-content: space-between; font-size: 1.3rem; }.modal-header.close-modal { font-size: 1.5rem; }.modal p+p { margin-top: 1rem; } /* ANIMATIONS –––––––––––––––––––––––––––––––––––––––––––––––––– */ [data-animation].modal-dialog { opacity: 0; transition: all 0.5s var(--bounceEasing); } [data-animation].is-visible.modal-dialog { opacity: 1; transition-delay: 0.2s; } [data-animation="slideInOutDown"].modal-dialog { transform: translateY(100%); } [data-animation="slideInOutTop"].modal-dialog { transform: translateY(-100%); } [data-animation="slideInOutLeft"].modal-dialog { transform: translateX(-100%); } [data-animation="slideInOutRight"].modal-dialog { transform: translateX(100%); } [data-animation="zoomInOut"].modal-dialog { transform: scale(0.2); } [data-animation="rotateInOutDown"].modal-dialog { transform-origin: top left; transform: rotate(-1turn); } [data-animation="mixInAnimations"].is-visible.modal-dialog { animation: mixInAnimations 2s 0.2s linear forwards; } [data-animation="slideInOutDown"].is-visible.modal-dialog, [data-animation="slideInOutTop"].is-visible.modal-dialog, [data-animation="slideInOutLeft"].is-visible.modal-dialog, [data-animation="slideInOutRight"].is-visible.modal-dialog, [data-animation="zoomInOut"].is-visible.modal-dialog, [data-animation="rotateInOutDown"].is-visible.modal-dialog { transform: none; } @keyframes mixInAnimations { 0% { transform: translateX(-100%); } 10% { transform: translateX(0); } 20% { transform: rotate(20deg); } 30% { transform: rotate(-20deg); } 40% { transform: rotate(15deg); } 50% { transform: rotate(-15deg); } 60% { transform: rotate(10deg); } 70% { transform: rotate(-10deg); } 80% { transform: rotate(5deg); } 90% { transform: rotate(-5deg); } 100% { transform: rotate(0deg); } } /* FOOTER –––––––––––––––––––––––––––––––––––––––––––––––––– */ footer { display: flex; align-items: center; justify-content: center; }.page-footer { position: fixed; bottom: 0; }.page-footer span { color: #e31b23; }

 <,DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-width. initial-scale=1:0"> <title>Library</title> <script src="https.//kit.fontawesome.com/2b4114baf6:js" crossorigin="anonymous"></script> <.-- Google fonts --> <link rel="preconnect" href="https.//fonts:googleapis.com"> <link rel="preconnect" href="https.//fonts:gstatic.com" crossorigin> <link href="https.//fonts?googleapis:com/css2,family=Montserrat,ital;wght@0,100;0,200;0,300;0,400;0,500;0,600;0,700;0,800;0,900;1,100;1,200;1,300;1,400;1,500;1,600;1,700;1,800:1,900&family=Noto+Sans,ital;wght@0,400;0,700;1,400:1,700&family=Open+Sans,ital;wght@0,300;0,400;0,500;0,600;0,700;0,800;1,300;1,400;1,500;1,600;1,700:1,800&family=Poppins,ital;wght@0,100;0,200;0,300;0,400;0,500;0,600;0,700;0,800;0,900;1,100;1,200;1,300;1,400;1,500;1,600;1,700;1,800:1;900&family=Roboto+Slab;wght@100;200;300;400;500;600;700:800,900&family=Roboto,ital;wght@0,100;0,300;0,400;0,500;0,700;0,900;1,100;1,300;1,400;1,500;1,700:1,900&family=Rubik,ital;wght@0,300;0,400;0,500;0,600;0,700;0,800;0,900;1,300;1,400;1,500;1,600;1,700;1,800:1,900&family=Source+Sans+Pro,ital;wght@0,200;0,300;0,400;0,600;0,700;0,900;1,200;1,300;1,400;1,600;1,700.1:900&display=swap" rel="stylesheet"> <.-- CSS Stylesheet --> <link href="styles.css" rel="stylesheet"> <.-- jQuery --> <script src="https.//ajax.googleapis.com/ajax/libs/jquery/3:6:0/jquery:min?js"></script> </head> <body> <h1>Library</h1> <div class="btn-group"> <button type="button" class="open-modal" data-open="modal1"> New Book </button> </div> <div class="btn-group"> <button class="open-modal" id="save-storage"> Save local storage </button> <button class="open-modal" id="delete-storage"> Delete local storage </button> </div> <:-- Library books container --> <div class="show-books"> </div> <:-- Modal code (popup box for new book form) --> <div class="modal" id="modal1" data-animation="slideInOutLeft"> <div class="modal-dialog"> <header class="modal-header"> Book Details <button class="close-modal" aria-label="close modal" data-close> ✕ </button> </header> <section class="modal-content"> <form class="bookcard"> <label>Title:</label> <input type="text" class="form-box" id="book-title" placeholder="Fight Club"> <label>Author.</label> <input type="text" class="form-box" id="book-author" placeholder="Chuck Palahniuk"> <label># of Pages.</label> <input type="number" class="form-box" id="book-pages" placeholder="208" min="1" max="14000"> <label>Have you read this book?:</label> <div class="radiobox"> <label class="radio-option1"><input type="radio" name="read" value="yes" id="bookreadyes" class='form-radio' checked> Yes</label> <label class="radio-option2"><input type="radio" name="read" value="no" id="bookreadno" class='form-radio'> No</label> </div> <label>Select card color (optional):</label> <select class="colorpicker"> <option value='default' selected disabled>Please select one</option> <option value="white">White (Default)</option> <option value="blue" id="option-blue">Blue</option> <option value="purple" id="option-purple">Purple</option> <option value="green" id="option-green">Green</option> <option value="grey" id="option-grey">Grey</option> <option value="red" id="option-red">Red</option> <option value="orange" id="option-orange">Orange</option> <option value="yellow" id="option-yellow">Yellow</option> <option value="dark" id="option-dark">Dark mode</option> </select> <p class="alertwords"></p> </form> </section> <footer class="modal-footer"> <button class="submitbtn">Submit</button> </footer> </div> </div> <footer class="page-footer"> <small>Made with <span>❤</span> by <a href="http://georgemartsoukos.com/" target="_blank">Sara Dunlop</a> </small> </footer> <!-- JS script --> <script src="script2.js"></script> </body> </html>

Answer 1

Here is the simple fix for you

let closeBtn = `<button type='button' class='close-default' onclick='libraryBooks.splice(libraryBooks.findIndex((book) => book.title === "${bookTitle}" && book.author === "${bookAuthor}"), 1);'>x</button>`;

i is getting from your array list

Just in case you don't understand what is template literals, I share the link here https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Template_literals

I also added an extra fix for your deleteLocalStorage . You need to clean up your libraryBooks array too.

function deleteLocalStorage() {
  libraryBooks = [] //here is the fix to clean up your array
  window.localStorage.clear();
  showBooks.textContent = "";
}

You can check my fixes here

https://jsfiddle.net/otywdekm/4/

Answer 2

Well, I made a good couple changes to your script and it works The main problem was that your close button wasn't given a listener that would be able to remove the book it's related to, solved that and also for fun added logic to automatically save to localStorage

The code's below but there's also a link to a working example

// Link DOM elements
const newBookBtn = document.querySelector('.newbook'); // New Book button
const showBooks = document.querySelector('.show-books'); // div container
const cardClose = document.querySelectorAll('.cardclose'); // button to close card
const openEls = document.querySelectorAll("[data-open]"); // for popup boxes
const closeEls = document.querySelectorAll("[data-close]"); // for popup boxes
const submitBtn = document.querySelector('.submitbtn'); // Submit button (in popup boxes)
const formBoxes = document.querySelectorAll('.form-box'); // Form box within popup box
const formRadio1 = document.querySelector('#bookreadyes'); // Form radio buttons within popup box
const isVisible = "is-visible"; // for popup boxes
const colorDropdown = document.querySelector('select'); // Color-picking dropdown in popup boxes
let libraryBooks = [], automaticallyUpdate = true; //change automaticallyUpdate to false to prevent automatic saving(on changes)


// localstorage buttons (save and delete)
const saveStorage = document.getElementById('save-storage');
const deleteStorage = document.getElementById('delete-storage');

// Button event listeners
saveStorage.addEventListener('click', updateLocalStorage);
deleteStorage.addEventListener('click', deleteLocalStorage);
submitBtn.addEventListener('click', addBookToLibrary);


// The Book constructor
function Book({title, author, pages, read, color}) {
  this.title = String(title)
  this.author = String(author)
  this.pages = Number(pages)
  this.read = read?"Read":"Not Read"
  this.color = String(color)
  this.info = function() {
    return `${this.title} by ${this.author}, ${this.pages} pages, ${this.read} with color ${this.color}`;
  }
}

//returns your close button with a listener that actually removes the book
//"<button type='button' class='close-default' onclick='$(this).parent().parent().remove();'>x</button>";
function closeBar(book){
  let btn=document.createElement('button')
  btn.className='close-default'
  btn.innerHTML='x' //wow almost forgot this
  btn.addEventListener('click',()=>{
    $(btn).parent().parent().remove()
    console.log(book,libraryBooks,libraryBooks.indexOf(book))
    libraryBooks.splice(libraryBooks.indexOf(book),1)
    if(automaticallyUpdate){updateLocalStorage()} //automatic saving
  })
  return btn //the button is returned to be placed in its arrangement
}


// Add book to library function.
function addBookToLibrary() {
  let color = colorDropdown.value;
  let bookTitle = document.querySelector('#book-title');
  let bookAuthor = document.querySelector('#book-author');
  let bookPages = document.querySelector('#book-pages');
  let bookRead = document.querySelector('#bookreadyes').checked; //true if checked, false if not checked
  let alertWords = document.querySelector('.alertwords'); // Alert if form elements are empty
    
  // Creating a new book object via the Book constructor
  let newBook = new Book({title:bookTitle.value, author:bookAuthor.value, pages:bookPages.value, read:bookRead, color});


  // If any form elements are empty, throw error and don't submit book. If none of them are empty, proceed.
  if (bookTitle.value.length === 0 || bookAuthor.value.length === 0 || bookPages.value.length === 0) {
      alertWords.textContent = 'Please fill in all fields.';
  } else {
      alertWords.textContent = '';
      document.querySelector('.modal.is-visible').classList.remove(isVisible); // Closes the modal
      formBoxes.forEach(formBox => {
          formBox.value = "";           // Sets the form values so they're blank the next time the New Book button is pressed
      });
      formRadio1.checked = true; // Set the radio buttons so that the "Yes" button is automatically selected (otherwise, the user's last choice will be selected)

      // Push the new book object into libraryBooks array
      libraryBooks.push(newBook);
      
      // The rest of the lines of code in this function create the actual book card on page
      const newCard = document.createElement('div');
      const newCardTitle = document.createElement('h4');
      const newCardAuthor = document.createElement('p');
      const newCardPages = document.createElement('p');
      const newCardRead = document.createElement('span');

      newCardTitle.setAttribute('class', 'title-style');
      newCardAuthor.setAttribute('class', 'author-style');
      newCardPages.setAttribute('class', 'pages-style');
      newCardRead.setAttribute('class', 'read-style');

      newCard.classList.add('isVisible', 'cardbox', colorPicker(newBook.color));
      showBooks.appendChild(newCard);

      const {title,author,pages,read}=newBook
      newCardTitle.innerHTML = `${title}`;
      let closeBtn = closeBar(newBook)
      newCardTitle.appendChild(closeBtn);
      newCardAuthor.innerHTML = `by ${author}`;
      newCardPages.innerHTML = `<strong>Pages</strong>: ${pages}`;
      newCardRead.innerHTML = `<strong>Status</strong>: ${read}`;
      
      
      newCard.appendChild(newCardTitle);
      newCard.appendChild(newCardAuthor);
      newCard.appendChild(newCardPages);
      newCard.appendChild(newCardRead);
      
      if(automaticallyUpdate){updateLocalStorage()} //automatic saving

   }
}



// Stuff for popup capability

for (const el of openEls) {
    el.addEventListener("click", function() {
        const modalId = this.dataset.open;
        document.getElementById(modalId).classList.add(isVisible);
    });
}

for (const el of closeEls) {
    el.addEventListener("click", function() {
        this.parentElement.parentElement.parentElement.classList.remove(isVisible);
    });
}

document.addEventListener("click", e => {
    if (e.target == document.querySelector(".modal.is-visible")) {
        document.querySelector(".modal.is-visible").classList.remove(isVisible);
    }
});

// Keyboard shortvut for modal: ESC key to close
document.addEventListener("keyup", e => {
    // if we press the ESC
    if (e.key == "Escape" && document.querySelector(".modal.is-visible")) {
        document.querySelector(".modal.is-visible").classList.remove(isVisible);
    }
});

cardClose.forEach(card => {
    card.addEventListener('click', function() {
        this.parentNode.parentNode.removeChild(this.parentNode.parentNode);
        return false;
    });
})


// Switch function for setting the background color of the book's card
let colors = {red:1, orange:1, yellow:1, green:1, blue:1, purple:1, dark:1, grey:1}
//the above variable saves a lot of lines in the colorPicker function
function colorPicker(color) {
    if(!colors[color]){return 'cardback-white'}
    return 'cardback-'+color
}


// Update local storage
function updateLocalStorage() {
    localStorage.setItem('books', JSON.stringify(libraryBooks));
}


// Delete local storage
function deleteLocalStorage() {
    window.localStorage.clear();
    showBooks.textContent = "";
}


// Get localStorage data and set it to the variable "data"
const data = JSON.parse(localStorage.getItem('books'))||[]
// the "||" in case there was nothing stored yet and it prevents an error from reading map from null
.map(book=>new Book( book )) //convert localStorage data to a list of "Book"s

// Load the saved local storage objects into cards (almost identical to addBookToLibrary())
function loadLocalStorage({title,author,pages,read,color}) {
    // EDIT: the for loops in this function are seemingly useless    
    var newBook=arguments[0]
    libraryBooks.push(newBook)
    // Create book card on page
    const newCard = document.createElement('div');
    const newCardTitle = document.createElement('h4');
    const newCardAuthor = document.createElement('p');
    const newCardPages = document.createElement('p');
    const newCardRead = document.createElement('span');

    newCardTitle.setAttribute('class', 'title-style');
    newCardAuthor.setAttribute('class', 'author-style');
    newCardPages.setAttribute('class', 'pages-style');
    newCardRead.setAttribute('class', 'read-style');
    
    newCard.classList.add('isVisible', 'cardbox', colorPicker(color));
    showBooks.appendChild(newCard);
     
    
    newCardTitle.innerHTML = `${title}`;
    const closeBtn = closeBar(newBook);
    newCardTitle.appendChild(closeBtn);
    newCardAuthor.innerHTML = `by ${author}`;
    newCardPages.innerHTML = `<strong>Pages</strong>: ${pages}`;
    newCardRead.innerHTML = `<strong>Status</strong>: ${read}`;
     
     newCard.appendChild(newCardTitle);
     newCard.appendChild(newCardAuthor);
     newCard.appendChild(newCardPages);
     newCard.appendChild(newCardRead);
}

// Required in order to load saved books onto page
for(let i = 0; i < data.length; i++) {
    loadLocalStorage(data[i]);
}

Answer 3

I checked out your demo, and what I think you can do is, while saving a book object you can pass in an property called id to identify the exact book from the collection.

So when you click on the x button you will get the details of that book which now has an id and you can filter it out.

Something as follows -

const filteredBooks = existingBooks.filter((el) => el.id !== book.id);
localstorage.setItem('books', filteredBooks);

Hope that works for you.

Answer 4

You Problem in delete specific book card

libraryBooks.splice(libraryBooks.indexOf(item), 1);

Thats not correct because

indexOf() compares searchElement to elements of the Array using strict equality (the same method used by the ===, or triple-equals, operator).

libraryBooks.indexOf always results in -1

the solution you can add index when you create book in book constructor and increment it in every book

[
{
index: 0
author: "00"
pages: "200"
read: "Read"
title: "00"
}
]

when create new object set index++ to able get the object directly and when delete

function deleteBook(book){
   libraryBooks.splice(book.index , 1)
}