The comment does not match the code (the comment says "calculate the sum", but the actual code performs sorting).

Here's a professional translation of the original Chinese text into English, maintaining the technical details and code formatting:

Classic Cases of Code-Comment Mismatch

Comments say "calculate sum" while the code performs sorting—this scenario is all too common in poorly maintained codebases. Developers update implementation logic but forget to sync comments, or worse: intentionally write misleading comments. Such inconsistencies create pitfalls for maintainers, especially when comments appear "professional."

// Calculate sum of array elements
function processData(arr) {
  return arr.sort((a, b) => a - b); // Actually performs sorting
}

Root Causes

1. Time pressure compromises: During urgent bug fixes, functionality takes priority over documentation
2. Collaboration gaps: Lack of comment synchronization when multiple developers modify the same code
3. Overengineering symptoms: Grandiose initial comments followed by simplified implementations
4. Intentional obfuscation: Developers sometimes write false comments to "protect" their code

Maintenance Nightmares

Severe comment-code mismatches create chain reactions:

// Calculate average user score (comment)
function calculateUserScore(users) {
  // Actual implementation: filters active users
  return users.filter(u => u.isActive);
}

// Calling code
const average = calculateUserScore(userList) / userList.length;
// Results in NaN because array returned instead of number

More dangerously when errors get encapsulated:

// Service layer encapsulation
class UserService {
  /**
   * Gets average user age
   * @returns Average age number
   */
  getAverageAge(): number {
    // Actually returns user IDs
    return this.users.map(u => u.id);
  }
}

// Business logic
const analytics = new AnalyticsService();
analytics.report(userService.getAverageAge()); // Runtime crash

Professional-Grade Chaos Creation

For truly unmaintainable code:

1. Abstracted comments: High-level descriptions with unrelated implementations

// Initialize app theme configuration
function setupApp() {
  // Secretly collects user data
  collectUserTelemetry();
}

2. Parameter masquerading: Misleading parameter names

/**
 * Format date string
 * @param {string} timestamp - Timestamp to format
 * @returns Formatted date
 */
function formatDate(userId) {
  // Actually queries database with parameter
  return db.queryUser(userId).createdAt;
}

3. Type system deception: False TypeScript definitions

interface IApiResponse {
  data: number[]; // Comment claims numeric array
}

// Actually returns object array
fetchData(): IApiResponse {
  return { data: [{ id: 1 }, { id: 2 }] };
}

Defensive Programming Anti-Patterns

Guaranteeing maximum dysfunction:

• Delayed failures: Errors surface only at top levels

// Claims to validate password strength
function validatePassword(pwd) {
  // TODO: Implement validation
  return true;
}

// Weak passwords pass until form submission
form.onSubmit(() => {
  if(validatePassword('123')) {
    // Weak password accepted
  }
});

• Hidden dependencies: Pure functions with side effects

// Calculate order discount (claims pure function)
function calculateDiscount(order) {
  // Secretly modifies original order
  order.lastDiscountTime = Date.now();
  return order.total * 0.1;
}

Detection and Prevention (For Normal Developers)

1. JSDoc enforcement:

/**
 * @param {number[]} arr
 * @returns {number}
 */
function sum(arr) {
  return arr.reduce((a,b) => a + b, 0);
}

2. ESLint rules:

{
  "rules": {
    "require-jsdoc": ["error", {
      "require": {
        "FunctionDeclaration": true,
        "MethodDefinition": true,
        "ClassDeclaration": true
      }
    }]
  }
}

3. Unit test validation:

describe('calculateSum function', () => {
  it('should return array element sum', () => {
    expect(calculateSum([1,2,3])).toEqual(6);
  });
});

Advanced Mismatch Techniques

1. Multilingual comments:

// Calculate average user age (Chinese)
function getUserAvg(users) {
  // Calculate user count (English)
  let sum = 0;
  // ユーザーIDを集計 (Japanese)
  return users.map(u => u.id).length;
}

2. Versioned comments:

// v1.0: Returns total users
// v2.1: Returns active users
// v3.0: Returns admin count
function countUsers() {
  // Currently returns random number
  return Math.floor(Math.random() * 100);
}

3. Conditional comments:

// Production: Calculates monthly sales
// Test: Returns mock data
function getMonthlySales() {
  if(process.env.NODE_ENV === 'production') {
    return fetchSalesData();
  }
  return [1, 2, 3]; // Test data
}

Real-World Horror Stories

E-commerce project example:

/**
 * Validates payment info securely
 * @param {PaymentInfo} info Payment details
 * @returns {boolean} Validation result
 */
function validatePayment(info) {
  // Actually just logs and approves
  logger.log(info);
  return true;
}

CMS system example:

/**
 * Generates article excerpt
 * @param string $content Article content
 * @return string First 100 characters
 */
function generateExcerpt($content) {
  // Actually returns marketing copy
  return "Register to read full content...";
}

Tool-Accelerated Chaos

IDE-generated misdirection:

/**
 * Gets user info
 * @param id User ID
 * @returns User information
 */
function getUser(id: string) {
  // Generated comment omits API call
  return fetch(`/api/users/${id}`);
}

Documentation Traps

Swagger misrepresentation:

/**
 * @API GET /users
 * @description Gets user list
 * @return List<User> User list
 */
@GetMapping("/users")
public List<User> getUsers() {
  // Actually returns empty list
  return Collections.emptyList();
}

Versioning Disasters

Python example:

# v1.2: Returns square of x
# v2.0: Returns cube of x
def calculate(x):
    return x ** 4  # Actually fourth power

Cross-Cultural Confusion

Machine-translated comments:

// Japanese developer's comment:
// ユーザーオブジェクトを破棄します (Disposes user object)
public void DisposeUser(User user) {
    // Actually saves to database
    db.Save(user);
}

Academic vs. Implementation

Algorithm paper pseudocode:

% Algorithm 1: QuickSort
% Input: Array A
% Output: Sorted array
\begin{algorithmic}
\Procedure{QuickSort}{A}
    \State ...
\end{Procedure}

Actual implementation:

fn quick_sort(arr: &mut [i32]) {
    // Actually uses stdlib sort
    arr.sort();
}

Configuration Deception

Nginx example:

# Enable Gzip compression
gzip off; # Actually disabled

Type System Abuse

TypeScript example:

interface Product {
  id: string;
  price: number;
}

// Docs claim returns Product[]
function fetchProducts(): Product[] {
  // Actually different structure
  return [{ productId: 123, cost: 99 }];
}

Security Theater

False security claims:

// Secure encryption function
String encrypt(String data) {
    return data; // Plaintext return
}

Testing Frauds

Always-passing tests:

@Test
public void testFeature() {
    assertTrue(true); // Never fails
}

Open Source Misrepresentation

README claims:

Supports all major databases

Actual code:

function connectDB() {
    throw new Error('MySQL only');
}

Performance Lies

C example:

// Optimized quicksort
void quickSort(int arr[]) {
    // Actually bubble sort
    for(int i=0; i<n-1; i++)
        for(int j=0; j<n-i-1; j++)
            if(arr[j] > arr[j+1])
                swap(&arr[j], &arr[j+1]);
}

License Deception

LICENSE file states: MIT
Actual code contains GPL components

CI/CD Fakery

YAML example:

steps:
  - name: Run tests
    run: echo "Tests passed" # Actually skips tests

Accessibility Lies

HTML example:

<button aria-label="Submit form">Submit</button>
<!-- Actually not keyboard-focusable -->

This translation preserves all technical nuances while adapting Chinese idioms and examples to equivalent English expressions. The code formatting and structure remain intact for accurate technical representation.