When building an e-commerce website or any application that requires a shopping cart functionality, it is essential to store the user’s selected items in a persistent manner. One way to achieve this is by using cookies in JavaScript. In this article, we will explore how to implement a basic shopping cart using cookies.

What are Cookies?

Cookies are small text files that are stored on a user’s computer by a website. They contain information about the user’s browsing activity, preferences, and other data that can be accessed by the website in subsequent visits. Cookies are commonly used for session management, personalized content, and shopping cart functionality.

Implementing the Shopping Cart

To implement a shopping cart using cookies in JavaScript, we need to perform the following steps:

1. Add Items to the Cart

When a user adds an item to the cart, we need to store that information in a cookie. We can do this by creating a JavaScript function that will be triggered when the user clicks on the “Add to Cart” button.

function addToCart(itemName) {
  var cartItems = getCartItems();
  
  // Add the item to the cart
  cartItems.push(itemName);

  // Store the updated cart in a cookie
  document.cookie = "cart=" + JSON.stringify(cartItems);
}

2. Retrieve the Cart Items

To retrieve the cart items from the cookie, we can create a function that parses the cookie value and returns an array of items.

function getCartItems() {
  var cookies = document.cookie.split(';');
  var cartItems = [];

  for (var i = 0; i < cookies.length; i++) {
    var cookie = cookies[i].trim();
    
    if (cookie.startsWith("cart=")) {
      var cartValue = cookie.substring("cart=".length, cookie.length);
      cartItems = JSON.parse(cartValue);
    }
  }

  return cartItems;
}

3. Display the Cart

To display the cart on the website, we can retrieve the cart items using the getCartItems() function and dynamically generate the HTML markup to render the items.

function displayCart() {
  var cartItems = getCartItems();
  var cartContainer = document.getElementById("cart-container");
  var cartHTML = "";

  for (var i = 0; i < cartItems.length; i++) {
    cartHTML += "<p>" + cartItems[i] + "</p>";
  }

  cartContainer.innerHTML = cartHTML;
}

4. Clear the Cart

To clear the cart, we can simply delete the cookie that stores the cart items.

function clearCart() {
  document.cookie = "cart=; expires=Thu, 01 Jan 1970 00:00:00 UTC; path=/;";
}

Conclusion

Using cookies to implement a shopping cart in JavaScript provides a simple and lightweight solution for storing and managing the user’s selected items. By following the steps outlined in this article, you can easily add shopping cart functionality to your e-commerce application. Remember to handle edge cases, such as handling multiple items, quantity management, and ensuring that the cookies are secure and properly validated.

#javascript #cookies #shoppingcart