Creating a comprehensive explanation for a 300-line codebase that incorporates classes, switch statements, and try-catch-finally statements can be quite extensive. I'll provide a detailed walkthrough of such a codebase in sections to make it easier to understand. Let's break it down:

Section 1: HTML Structure and Initial Setup

In the HTML section, we set up the structure for a bank landing page with a menu button functionality. We've included a navigation menu with a toggle button for small screens. The navigation menu becomes visible when the menu button is clicked. This HTML structure forms the foundation for our web page.

Section 2: Basic Styles

In this CSS section, we define basic styles to reset default styles and provide a consistent look and feel. We ensure that there is no margin or padding by default for body, h1, and p elements. We set a background color for the body and apply styling to the header section, including a background color, text color, and box-shadow.

Section 3: Header and Navigation

Here, we style the header and navigation menu. The navigation menu is designed to be hidden by default and displayed as a flexbox container when the menu button is clicked (for responsive design on smaller screens). We also style the menu toggle button with three lines, making it look like a typical menu button.

Section 4: Container and Landing Page Content

In this part, we style the main content container that holds our landing page content. We define the container's maximum width, margins, padding, background color, and box-shadow to give it a card-like appearance. The landing page content, including a welcoming heading, a brief description, and a call-to-action button, is styled to be visually appealing.

Section 5: Responsive Design

This section focuses on responsive design. We ensure that the menu button becomes visible on screens with a maximum width of 768px, making it suitable for mobile devices. When the menu button is clicked, the menu list is displayed vertically, and each menu item has appropriate margins and styling for better readability on smaller screens.

Section 6: JavaScript

Here is the JavaScript portion of our codebase, where we incorporate classes, switch statements, and try-catch-finally statements to provide interactive functionality to the landing page.

  • Class BankAccount We define a BankAccount class that represents a bank account. It has properties like accountHolder, accountType, balance, and transactionHistory. The class includes methods deposit and withdraw for handling financial transactions, with proper validation to ensure the user inputs valid amounts and checks for insufficient funds.

  • Event Listeners We add event listeners to the "Deposit" and "Withdraw" buttons. When a user clicks these buttons, we try to perform a transaction using the deposit or withdraw methods of the BankAccount class. We catch any errors (such as invalid input or insufficient funds) using try-catch blocks and display appropriate error messages or success messages to the user.

  • Update Functions We have functions to update the account details (account holder, type, balance) and display the transaction history dynamically in response to user actions.

  • HTML Interaction : Finally, we interact with the HTML by updating elements' text content and styles to provide feedback to the user. Messages about successful transactions or errors are displayed in a message container.