• JS Lab: Library

JS Lab: Library

In this lab, similarly to the Python lab, you’ll be working on a simple “database” for a library to understand CRUD operations in relation to representing redundant, similar data under one structure – an abstraction.

For JavaScript, you’ll have to open the web console from Developer Tools (ctrl + shift + p -> Developer: Toggle developer tools).

%%js
// Our "database" is an array of objects, each representing a book in a library.
let library = [
    { title: "1984", author: "George Orwell", checkedOut: false },
    { title: "To Kill a Mockingbird", author: "Harper Lee", checkedOut: true },
    { title: "The Great Gatsby", author: "F. Scott Fitzgerald", checkedOut: false }
];

// Function to display all books
function displayLibrary(lib) {
    console.log("\nAll books in the library:");
    lib.forEach((book, i) => {
        console.log(`Index ${i}:`, book);
    });
}

// Function to add a new book
function addBook(lib) {
    let title = prompt("Enter book title:");
    let author = prompt("Enter author:");
    let checkedOut = prompt("Is the book checked out? (yes/no):").toLowerCase() === "yes";
    
    let newBook = { title, author, checkedOut };
    lib.push(newBook);
    console.log("✅ Book added:", newBook);
}

// Function to find a book by title
function findBook(lib, searchTitle) {
    let book = lib.find(b => b.title.toLowerCase() === searchTitle.toLowerCase());
    if (book) {
        console.log("🔎 Found book:", book);
        return book;
    } else {
        console.log("❌ Book not found.");
        return null;
    }
}

// Function to update a book's checkedOut status
function updateBook(lib, searchTitle) {
    let book = lib.find(b => b.title.toLowerCase() === searchTitle.toLowerCase());
    if (book) {
        let newStatus = prompt("Is the book checked out? (yes/no):").toLowerCase() === "yes";
        book.checkedOut = newStatus;
        console.log("✅ Book updated:", book);
    } else {
        console.log("❌ Book not found.");
    }
}

// Function to delete a book
function deleteBook(lib, searchTitle) {
    let index = lib.findIndex(b => b.title.toLowerCase() === searchTitle.toLowerCase());
    if (index !== -1) {
        let removed = lib.splice(index, 1);
        console.log("🗑️ Book deleted:", removed[0]);
    } else {
        console.log("❌ Book not found.");
    }
}

// Example usage
displayLibrary(library);
// Uncomment these when running in a browser environment where prompt() works:
// addBook(library);
// findBook(library, "1984");
// updateBook(library, "To Kill a Mockingbird");
// deleteBook(library, "The Great Gatsby");

<IPython.core.display.Javascript object>