CamelCase vs Snake_Case vs Kebab-Case: A Developer's Guide

// Variable declarations
let userName = 'John Doe';
const maxLoginAttempts = 5;
let isUserLoggedIn = false;

// Function declarations
function calculateTotalPrice(items, taxRate) {
  return items.reduce((total, item) => total + item.price, 0) * (1 + taxRate);
}

// Object methods
const user = {
  firstName: 'Jane',
  lastName: 'Smith',
  getFullName() {
    return `${this.firstName} ${this.lastName}`;
  }
};

public class UserService {
    private String emailAddress;
    private int accountBalance;
    
    public void sendWelcomeEmail(String recipientName) {
        String messageBody = "Welcome " + recipientName;
        // Email sending logic
    }
    
    public int calculateMonthlyPayment(int loanAmount, double interestRate) {
        return loanAmount * interestRate / 12;
    }
}

# Variable declarations
user_name = 'Alice Johnson'
max_retry_attempts = 3
is_authenticated = True

# Function definitions
def calculate_discount_price(original_price, discount_percentage):
    discount_amount = original_price * (discount_percentage / 100)
    return original_price - discount_amount

# Class with methods (note: class names use PascalCase)
class UserAccount:
    def __init__(self, email_address, account_type):
        self.email_address = email_address
        self.account_type = account_type
    
    def send_verification_email(self):
        verification_code = self.generate_random_code()
        # Send email logic

-- Table creation with snake_case columns
CREATE TABLE user_profiles (
    user_id INT PRIMARY KEY,
    first_name VARCHAR(50),
    last_name VARCHAR(50),
    email_address VARCHAR(100),
    date_of_birth DATE,
    account_created_at TIMESTAMP,
    is_email_verified BOOLEAN
);

-- Query example
SELECT 
    u.user_id,
    u.first_name,
    u.last_name,
    o.order_total
FROM user_profiles u
JOIN order_history o ON u.user_id = o.user_id
WHERE o.order_status = 'completed';

# Variable assignments
user_email = 'user@example.com'
total_items = 42
is_premium_member = true

# Method definition
def calculate_shipping_cost(weight_in_kg, destination_country)
  base_rate = 5.00
  per_kg_rate = 2.50
  
  base_rate + (weight_in_kg * per_kg_rate)
end

# Class definition
class ShoppingCart
  attr_accessor :cart_items, :discount_code
  
  def add_item_to_cart(item)
    @cart_items << item
  end
end

// SEO-friendly URL structures
https://example.com/blog/how-to-learn-javascript
https://example.com/products/wireless-bluetooth-headphones
https://example.com/user-profile/settings/privacy-preferences

// API endpoint naming
GET /api/v1/user-accounts
POST /api/v1/create-order
PUT /api/v1/update-shipping-address
DELETE /api/v1/remove-cart-item

// Next.js / React Router file-based routing
/pages/about-us.tsx
/pages/contact-form.tsx
/pages/blog/[post-slug].tsx

/* Component classes */
.navigation-bar {
  display: flex;
  background-color: #ffffff;
}

.navigation-bar__menu-item {
  padding: 10px 20px;
}

.navigation-bar__menu-item--active {
  font-weight: bold;
  color: #0066cc;
}

/* Utility classes */
.text-center { text-align: center; }
.margin-top-large { margin-top: 2rem; }
.background-primary-color { background: var(--primary-color); }

/* Animation names */
@keyframes fade-in-up {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

<!-- Custom data attributes -->
<div 
  class="product-card"
  data-product-id="12345"
  data-category-name="electronics"
  data-is-in-stock="true">
  <h3>Wireless Headphones</h3>
</div>

<!-- ARIA attributes for accessibility -->
<button
  aria-label="Close navigation menu"
  aria-expanded="true"
  aria-controls="mobile-menu">
  Close
</button>

<!-- Custom Web Components -->
<user-profile-card user-id="789"></user-profile-card>
<shopping-cart-widget></shopping-cart-widget>

// package.json - npm package names
{
  "name": "react-router-dom",
  "dependencies": {
    "lodash-es": "^4.17.21",
    "date-fns": "^2.29.0",
    "styled-components": "^5.3.0"
  }
}

// Project file structure
my-awesome-project/
├── user-authentication.js
├── database-connection.js
├── email-service-config.js
└── payment-gateway-integration.js