Golden Rules to Write Clean Code

Clean code is essential for maintainability, scalability, and collaboration in software development. Below are six fundamental principles to follow, along with practical commands, code snippets, and best practices.

1. Separation of Concerns (SOC)

Break down complex programs into smaller, independent units, each handling a specific task.

Example in Python:

 Bad: Mixing logic 
def process_data_and_save(data): 
 Process data 
processed = [x  2 for x in data] 
 Save to file 
with open("output.txt", "w") as f: 
f.write(str(processed))

Good: Separated concerns 
def process_data(data): 
return [x  2 for x in data]

def save_data(data, filename): 
with open(filename, "w") as f: 
f.write(str(data)) 

Linux Command to Check File Contents:

cat output.txt 

2. Document Your Code (DYC)

Use comments and docstrings to explain complex logic.

Example in Bash:

!/bin/bash 
 This script backs up the /var/log directory 
tar -czf /backup/logs_$(date +%F).tar.gz /var/log 

Verify Backup:

ls -lh /backup 

3. Don’t Repeat Yourself (DRY)

Avoid redundancy by using functions and libraries.

Example in JavaScript:

// Bad: Repeated code 
console.log("User: " + user1); 
console.log("User: " + user2);

// Good: DRY approach 
function logUser(user) { 
console.log("User: " + user); 
} 
logUser(user1); 
logUser(user2); 

Windows PowerShell Function:

function Get-DiskSpace { 
param ([bash]$drive) 
Get-WmiObject Win32_LogicalDisk -Filter "DeviceID='$drive'" | Select-Object FreeSpace 
} 
Get-DiskSpace "C:" 

4. Keep It Simple, Stupid (KISS)

Prioritize readability over cleverness.

Example in Python:

 Bad: Overly complex 
result = [x for x in range(100) if x % 2 == 0 and x % 5 == 0]

Good: Simple and clear 
even_and_divisible_by_5 = [] 
for x in range(100): 
if x % 2 == 0 and x % 5 == 0: 
even_and_divisible_by_5.append(x) 

Linux Command to List Files:

ls -la 

5. Test Driven Development (TDD)

Write tests before implementation.

Example in Python (using `pytest`):

 test_math.py 
def test_add(): 
assert add(2, 3) == 5

math.py 
def add(a, b): 
return a + b 

Run Tests:

pytest test_math.py 

6. You Ain’t Gonna Need It (YAGNI)

Avoid over-engineering.

Example in Git:

 Instead of creating multiple branches prematurely: 
git checkout -b feature/new-login 
 Only branch when needed. 

You Should Know:

• Linux:

  grep -r "error" /var/log  Search for errors in logs 
  chmod 600 ~/.ssh/id_rsa  Secure SSH key 
  

• Windows:

  netstat -ano | findstr "LISTENING"  Check open ports 
  

• Git Best Practices:

  git commit -m "fix: resolve login bug"  Use semantic commits 
  

What Undercode Say:

Clean code is not just about syntax—it’s about discipline. Use SOC to modularize, DYC to clarify, DRY to optimize, KISS to simplify, TDD to validate, and YAGNI to avoid waste. Master these, and your code will be robust and maintainable.

Expected Output:

• Well-structured, documented, and efficient code.
• Reduced bugs and easier debugging.
• Improved team collaboration.

Relevant URL:

System Design Template

References:

Reported By: Nk Systemdesign – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅

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