Create Shopping Cart from Scratch with Code Examples

You can create shopping cart features from scratch using html, CSS, and JavaScript, even if you are just starting out. Many beginners face challenges like confusing checkout steps, limited payment methods, and a lack of user-friendly design. When you build your own shopping cart, you learn how to solve these problems and improve user experience. Follow along to see how html and simple steps can help you create shopping cart solutions that work on any device.

Key Takeaways

• Start building your shopping cart with basic HTML, CSS, and JavaScript skills and improve as you go.

• Organize your project files clearly using folders for HTML, CSS, JavaScript, and images to keep your work neat.

• Use JavaScript to add, update, and remove products in the cart while showing real-time totals for a smooth user experience.

• Save cart data in the browser with localStorage so users keep their items even after refreshing or closing the page.

• Test your shopping cart carefully on different devices and browsers to fix issues and make shopping easy and secure.

Prerequisites

Skills Needed

Before you start building a shopping cart, you need to learn some basic web development skills. These skills help you create a strong foundation for your project. You will use html to build the structure of your shopping cart. You will style your pages with CSS. You will add interactive features with javascript. Here is a list of important skills you should focus on:

1. Client-side development: Learn how to use html, CSS, and javascript to create a user interface. You will make your shopping cart look good and work smoothly.

2. Responsive design: Make sure your shopping cart works well on phones, tablets, and computers.

3. Testing and deployment: Test your shopping cart to find and fix problems. Deploy your project so others can use it.

Tip: You do not need to master every skill before you begin. Start with the basics and improve as you build your project.

Tools Setup

You need the right tools to develop and test your shopping cart. A good code editor helps you write and organize your html, CSS, and javascript files. You also need a browser to see how your shopping cart works. The table below shows some popular tools and their features:

Google Chrome is a top choice for testing your shopping cart. Chrome DevTools lets you inspect html, CSS, and javascript. You can fix layout issues and debug your code easily. The Convert Experiences Debugger Extension helps you test ecommerce features and solve page loading problems.

Note: You can use any editor or browser you like, but starting with Visual Studio Code and Chrome makes learning easier.

Project Overview

Features

When you create shopping cart functionality, you unlock many useful features for your ecommerce site. A basic shopping cart lets you add and remove products, update quantities, and see the total price. You can view all items in one place before you check out. This makes shopping easier for your users.

Advanced shopping carts offer even more. You can show product thumbnails so shoppers see what they buy. Progress indicators guide users through checkout steps. Editable buttons let users change their choices quickly. Many carts work well on mobile devices, so people can shop anywhere. Secure payment options, trust badges, and encrypted data keep information safe. Some carts suggest related products or special offers, helping you increase sales. You can also track important numbers like cart abandonment rate and conversion rate. These features help you improve your ecommerce business.

Tip: Start with basic features. Add advanced options as you learn more and your project grows.

What You’ll Build

You will build a shopping cart using HTML, CSS, and JavaScript. Your cart will have a main container that holds everything. Inside, you will see a title, a list of products, and controls for each item. Each product will show an image, name, price, and buttons to change the quantity or remove the item. You will also add a section that displays the total price.

The structure looks like this:

• A main div wraps the shopping cart UI.

• Each product sits in its own box with an image and details.

• Plus and minus buttons let you adjust how many of each product you want.

• A checkout area shows the total and a button to finish the purchase.

You will use JavaScript to manage the list of products, update the cart, and handle user actions. If you want to try a react project later, you can use the same ideas and build a more dynamic cart. Many modern ecommerce sites use react for fast updates and smooth user experiences. You will see how easy it is to create shopping cart features that work for any store.

Setup to Create Shopping Cart

Folder Structure

A well-organized folder structure helps you keep your project clean and easy to manage. When you create shopping cart features, you want to separate your files by type. Follow these steps to set up your folders:

1. Make a main project folder. You can name it something like ecommerce-website.

2. Place your main index.html file inside this folder.

3. Create three subfolders: css, js, and images.

4. Put your main stylesheet, such as style.css, inside the css folder.

5. Place your main JavaScript file, like script.js, inside the js folder.

6. Store all your product images in the images folder.

7. Use lowercase letters and hyphens for all file and folder names. This keeps everything consistent and easy to read.

Tip: If you want to add more styles or scripts later, you can create extra folders inside css or js for themes or page-specific files.

This structure makes it simple to find your files and helps your project grow without confusion.

Boilerplate Code

You need some basic code to start your shopping cart project. Begin with a simple html file that links to your CSS and JavaScript files. You can also use Google Fonts, like Roboto, for a modern look. Here is a sample index.html file:

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Shopping Cart</title>
  <link href="https://fonts.googleapis.com/css?family=Roboto:400,700&display=swap" rel="stylesheet">
  <link rel="stylesheet" href="css/style.css">
</head>
<body>
  <div id="cart-container"></div>
  <script src="js/script.js"></script>
</body>
</html>

You can use this table to see what each part of your starter code does:

This setup gives you a strong base to build and test your shopping cart. You can now move on to adding products and interactive features.

Shopping Cart UI

Product List

You want your shopping cart ui to look clean and easy to use. Start by building a product list that shows each item clearly. Using html and css3, you can create a layout that displays product images, names, prices, and other important details. Good product display helps users find what they need fast. Show each product in its own box with enough space around it. Use the Roboto font for a modern style.

Here are some best practices for your product list:

1. Show a clear image, name, and price for each product.

2. Keep information short so users do not feel overwhelmed.

3. Add buttons or icons to let users change quantity or remove items.

4. Make sure the layout works well on phones and computers for a responsive shopping cart.

5. Place a “Continue Shopping” button so users can return to browsing easily.

You can use this sample html to start your shopping cart products list:

<div class="product-list">
  <div class="product-item">
    <img src="images/shirt.jpg" alt="Shirt">
    <h3>Classic Shirt</h3>
    <p>$19.99</p>
    <button class="add-to-cart">Add to Cart</button>
  </div>
  <!-- Add more product-item blocks here -->
</div>

Tip: Use tables or grids in your css to keep your shopping cart ui organized and easy to scan.

Add to Cart Button

The add to cart button is one of the most important parts of your shopping cart ui. Place this button near the product details and price. Make it large and use a color that stands out from the rest of the ui. Use clear words like “Add to Cart” so users know what will happen when they click.

Follow these tips for a great add to cart button:

1. Use a bright color that fits your brand but stands out on the page.

2. Make the button big enough for users to tap on phones and click on computers.

3. Put the button close to the product name and price for easy access.

4. Leave enough white space around the button so it does not blend in with other elements.

5. Use action words to encourage users to add items to their cart.

A good shopping cart ui makes it easy for users to add products and see them in the cart right away. This helps users trust your site and enjoy shopping.

Shopping Cart Functionality

Building a shopping cart with JavaScript helps you understand how real online stores work. You can create shopping cart features that let users add products, see their cart, change quantities, remove items, and view the real-time purchase amount. This section shows you how to add these features step by step.

Add Items

You need a way to add products to your shopping cart when users click the "Add to Cart" button. JavaScript makes this easy. You can use an array to store the products that users select. When someone clicks the button, you push the product object into the cart array.

A practical approach involves using DOM manipulation to link 'Add to Cart' buttons with their respective product elements. When a button is clicked, the parent product element is identified, and the product object is pushed into a cart array. Then, a loop over the cart array can be used to display or update the cart contents.

Here is a simple example:

let cart = [];

function addToCart(product) {
  cart.push(product);
  updateCartDisplay();
}

You can also use an object to track quantities by product ID. This keeps your cart organized and makes it easy to update quantities later.

const cartItems = {};

function addItemToCart(id) {
  cartItems[id] ? cartItems[id]++ : cartItems[id] = 1;
  setCart();
}

Both methods work well. You can choose the one that fits your project best.

Display Cart

You want users to see what they have in their shopping cart. You can use JavaScript to loop through the cart array or object and show each product in the UI. This makes the shopping experience clear and easy.

1. Place the shopping cart icon in the top-right corner of your page. This matches what users expect.

2. Show the number of items in the cart. Update this number every time someone adds or removes a product.

3. Give users feedback when they add to shopping cart. Show a quick message or animation so they know it worked.

4. Use a mini-cart or a slide-in window. This lets users see their cart without leaving the page.

Here is a sample function to display the cart:

function updateCartDisplay() {
  const cartContainer = document.getElementById('cart-container');
  cartContainer.innerHTML = '';
  cart.forEach(item => {
    cartContainer.innerHTML += `
      <div class="cart-item">
        <span>${item.name}</span>
        <span>${item.price}</span>
      </div>
    `;
  });
}

Tip: Adopt a mobile-first design with larger buttons and simple layouts. This helps users on phones and tablets.

Update Quantity

Users often want to buy more than one of a product. You can let them change the quantity in the shopping cart. JavaScript event listeners on plus and minus buttons help you do this. When a user clicks these buttons, you update the quantity in your cart object and refresh the UI.

A common approach is to use a global object that tracks each product's count. When users change the quantity, you update the count and recalculate the total price. The cart display updates right away, so users always see the correct information.

function updateCartItem(id, newQuantity) {
  if (cartItems[id]) {
    cartItems[id] = newQuantity;
    setCart();
  }
}

This method keeps your cart accurate and prevents mistakes. You can also use unit tests with console.assert to check that your code works as expected.

Remove Items

Sometimes users change their minds and want to remove a product from the shopping cart. You can let them do this with a "Remove" button next to each item. When clicked, JavaScript removes the product from the cart array or object and updates the UI.

This table shows different ways to remove items. You can pick the one that matches your cart design.

Total Price

You want users to see the real-time purchase amount as they shop. JavaScript helps you calculate the total price by adding up the prices of all items in the cart. Every time the cart changes, you update the total in the UI.

1. Loop through the cart and sum the prices.

2. Replace the total price element's content instead of adding new elements each time.

3. Use innerHTML to update the total price quickly.

Here is a code example:

function displayTotal() {
  let total = 0;
  for (let i = 0; i < cart.length; i++) {
    total += cart[i].price;
  }
  const totalPriceDom = document.getElementById('total-price');
  totalPriceDom.innerHTML = `<p class="totalPrice">Total price: ${total}</p>`;
}

This method keeps your total price accurate and updates it in real time. You can also use this logic in a react project, where the UI updates automatically when the cart changes.

Note: React makes it easy to manage state and update the UI. You can use the same logic from this JavaScript code in your react components. Many modern ecommerce sites use react for fast and smooth shopping cart experiences.

You now know how to create shopping cart features with JavaScript. You can add items, display the cart, update quantities, remove products, and show the real-time purchase amount. These skills help you build a strong foundation for any ecommerce project, whether you use plain JavaScript or move on to react.

Persist Shopping Cart Data

Use localStorage

You want your users to keep their cart items even after they close or refresh the browser. The localStorage API helps you do this. It stores data in the browser with no expiration date. This means your users can come back later and still see their cart items. You can use localStorage to save things like product IDs, quantities, and prices.

Here is a table that shows the advantages and limitations of using localStorage:

localStorage works best for non-sensitive data. You can use it for things like UI preferences, cached product lists, or saving a shopping cart. Always check if the data you store is safe to be seen by anyone using the browser.

Tip: localStorage does not have a built-in expiration. Data stays until you or the user clear it.

Restore Cart

You can restore the cart data when users return to your site. This makes shopping easier and faster. When the page loads, you check localStorage for saved cart data. If you find it, you load it into your cart. If not, you start with an empty cart.

• localStorage is best for non-sensitive data that does not risk privacy.

• It is ideal for saving things like UI themes, cached product lists, and feature flags.

• Data in localStorage is open to any JavaScript on the page, so always keep security in mind.

• There is no expiration, so old data can stay until cleared.

• Use cookies with security flags for sensitive data.

“To restore shopping cart data from localStorage on page reload, initialize your state by retrieving and parsing the stored cart data, returning an empty array if none exists. When adding items, update both the state and localStorage to keep them in sync. Use an effect hook or similar method to save the cart state to localStorage whenever it changes. This ensures persistence of cart items across page reloads.”

You can use this simple code to restore your cart:

function loadCart() {
  const savedCart = localStorage.getItem('cart');
  return savedCart ? JSON.parse(savedCart) : [];
}

This approach helps your users enjoy a smooth and reliable shopping experience.

Enhance Shopping Cart

Validation

You want your shopping cart to accept only correct information. Input validation helps you catch mistakes before they cause problems. You can use several techniques to make forms safer and easier for users.

1. Combine input validation with autocompletion. For example, address and zip code autocomplete can speed up checkout and reduce errors.

2. Check formats for important fields like VAT numbers, phone numbers, and postal codes. This keeps your data accurate.

3. Use cross-field validation. Make sure email addresses match so order confirmations reach the right person.

4. Apply conditional rules. Shipping and billing addresses may need different checks.

5. Show inline validation as users fill out forms. Display errors only after a user leaves a field to avoid confusion.

6. Limit validation to essential fields. Too many rules can frustrate users and increase cart abandonment.

7. Give clear and friendly error messages. Help users fix mistakes quickly.

8. Use libraries such as Parsley.js for front-end validation. These tools work well with javascript and react.

9. Test and improve your validation strategies often. Balance security with ease of use.

Good validation helps users complete their orders faster and with fewer mistakes.

Error Handling

You need to handle errors gracefully in your shopping cart. Many users leave their carts if they see confusing messages or face problems during checkout.

• Website errors or crashes during checkout cause frustration. You should test your payment process often and make sure it works on all devices.

• Complicated checkout steps lead to more abandoned carts. You can simplify the process by reducing screens and using autofill for addresses.

• Forced account creation makes users leave. Offer guest checkout and easy sign-up options.

• Distracting links during checkout confuse users. Remove unrelated links and keep navigation simple.

• Lack of security causes distrust. Display safety seals and use secure payment gateways.

• Clear calls to action help users finish their purchase. Make buttons easy to find and test different designs in react.

Clear communication about shipping, taxes, and pricing reduces confusion and helps users trust your site.

OOP Approach

You can make your shopping cart code easier to manage by using object-oriented programming. OOP organizes your code into classes that group related data and actions. This keeps your code clean and prevents accidental changes.

Encapsulation hides details and exposes only what you need. Inheritance lets you reuse and extend features, so you do not repeat code. Polymorphism allows you to use the same interface for different product types. Abstraction simplifies complex ideas into easy-to-use parts.

For example, in react, you can create classes for ShoppingCart and Checkout. You can add new features, such as discounts, without changing existing code. This modular design makes debugging and adding features easier. The Principle of Least Knowledge helps you keep parts of your code separate. Each part talks only to its closest friends, which makes changes safer and testing simpler.

You can use OOP principles in react or other languages to build a flexible and scalable shopping cart. This approach helps you create code that grows with your project.

Payment Integration

When you reach the checkout section, you want to give your customers a smooth and secure way to pay. A good payment integration helps you reduce cart abandonment and increase sales. You can choose from many payment options and gateways to fit your needs.

Payment Options

You should offer several payment options in your checkout section. This gives your customers flexibility and makes the checkout process easier. Here are some of the most popular choices for small businesses:

• Credit card payments work with third-party processors like Square, PayPal, and Stripe. These are secure and widely accepted.

• Mobile payment options such as Apple Pay, Android Pay, and Samsung Pay let customers pay quickly with their phones.

• ACH or eCheck payments allow direct bank transfers. These often have lower fees than credit cards.

• Digital wallets help customers check out faster and keep their information safe.

• Many platforms support features like recurring payments, payment plans, and email invoicing. These features make your checkout section more flexible.

Shopping cart platforms like Volusion let you connect with over 160 payment gateways. This means you can meet many customer preferences. You can also customize your storefront and offer a mobile version for easy shopping.

Tip: Integrating multiple payment methods such as credit cards, mobile payments, and digital wallets in your checkout section helps you provide a seamless experience. This reduces cart abandonment and increases customer satisfaction.

Payment Gateway

A payment gateway connects your shopping cart to the payment processor. You need to pick a gateway that matches your business needs and is easy to set up in your checkout section. Here is a table that shows some leading payment gateways and their features:

You can integrate these gateways in your checkout section by embedding JavaScript code, using APIs, or redirecting to hosted payment pages. Most gateways require API credentials and PCI DSS compliance. You should also use encryption and tokenization to keep payment data safe.

When you build your cart checkout, you want to make it easy for users to proceed to payment. A clear and simple checkout section with trusted payment gateways helps you build trust and boost sales.

Complete Code Example

You can build a complete shopping cart using react. This example shows you how to organize your code and create a simple cart that works well for learning. You will see how each part fits together and how you can update the cart as users shop.

Here are the main components you need:

• Header: Shows your store logo and a CartWidget. The CartWidget displays the number of products in the cart.

• Cart: Renders the main shopping page. It lists products in rows, lets users change quantities, and shows the total price.

• Quantifier: Adds plus and minus buttons. Users can adjust the quantity or remove items from the cart.

• Loader: Displays a loading animation while product data loads.

• Footer: Shares author information and copyright.

You should keep each component in its own folder. This modular design makes your react project easier to manage. You can use CSS Modules to style each part without mixing up your styles.

Here is a simple react code example for the Cart component:

import React, { useState } from 'react';

function Cart({ products }) {
  const [cart, setCart] = useState({});
  function updateQuantity(id, qty) {
    setCart(prev => ({ ...prev, [id]: qty }));
  }
  function getTotal() {
    return Object.entries(cart)
      .reduce((sum, [id, qty]) => sum + products[id].price * qty, 0)
      .toFixed(2);
  }
  return (
    <div>
      {products.map((product, idx) => (
        <div key={product.id}>
          <span>{product.name}</span>
          <Quantifier
            quantity={cart[product.id] || 0}
            onChange={qty => updateQuantity(product.id, qty)}
          />
          <span>£{product.price}</span>
        </div>
      ))}
      <div>Total: £{getTotal()}</div>
    </div>
  );
}

Tip: You can add backend entities like product, customer, order, and cart if you want to connect your react app to a database.

This example helps you learn how state management and UI updates work in react. You can change quantities, see the total price, and organize your code for future growth.

Test Shopping Cart

Manual Testing

Manual testing helps you make sure your shopping cart works as expected. You check each feature by hand, just like a real user. This process lets you find problems that automated tests might miss. You can see how the cart behaves on different devices and browsers.

Here is a table that shows important manual testing strategies:

You can also group your test cases by type:

Manual testing is important for several reasons:

1. You make sure the checkout and payment steps are smooth, which helps prevent users from leaving their carts.

2. You check every payment option, error message, and order confirmation by hand.

3. You test the cart on different browsers and devices to keep the experience consistent.

4. You find rare problems, like high-traffic issues or tricky user actions, that automated tests might miss.

5. You improve customer satisfaction and help your store stand out.

Manual testing gives you confidence that your shopping cart works well for everyone.

Common Issues

When you test your shopping cart, you may find some common problems. These issues can affect how users shop and pay. Fixing them helps you build trust and keep customers happy.

• Users sometimes cannot add, remove, or change item quantities without errors.

• The cart may not sync across tabs or sessions, causing confusion.

• Checkout pages might not load right, or some fields and checks may not work.

• Payment gateways can have problems like wrong charges or missing success messages.

• Bugs in integration can cause stock mismatches or break tracking and analytics.

• Security issues, such as data leaks or attacks, can put user information at risk.

Here is a table that shows frequent issues by category:

Regular testing and quick fixes help you avoid these issues and create a better shopping experience for your users.

You have learned the key steps to build a shopping cart from scratch. Start with planning, then add core features like product management and checkout. Use clear code and test each part. Try different layouts and checkout flows to see what works best. Add security and make checkout simple for users. Next, connect your cart to a backend or try using frameworks. Understanding these basics helps you create better checkout experiences and grow your skills.

FAQ

How do you add more products to the shopping cart?

You can add more products by creating new product items in your HTML. Update the product list section and use the same JavaScript functions to handle the new items.

Can you use this shopping cart on mobile devices?

Yes! The shopping cart works on phones and tablets. Responsive CSS makes sure the layout fits any screen size. Test your cart on different devices for the best results.

What happens if you refresh the page?

The cart uses localStorage. When you refresh, your cart items stay saved. You do not lose your selections. This helps you continue shopping without starting over.

Do you need a backend to use this shopping cart?

No, you do not need a backend for basic features. The cart runs in your browser with HTML, CSS, and JavaScript. If you want to save orders or connect to a database, you can add a backend later.

See Also

Revolutionizing Online Store Operations With AI-Driven E-Commerce Solutions

Essential Fundamentals Of Corner Stores And Their Importance

Cloudpick Technology Enables Seamless Cashier-Free Shopping Experience

Tracing The Development And Growth Of Self-Checkout Systems

Starting An AI-Enabled Corner Store With Low Initial Costs