Clean Code

Let me start by [Marin Fowler] quote about clean code.

"Any fool can write code that a computer can understand.
Good programmers write code that humans can understand."

It is surprising how few words can illustrate what clean code is. Writing code human can understand. Period.

Often times, we as developers find ourselves in front of code written by others. We always fail to understand it thus ended completely refactoring the code unless we are lucky in copy paste operations.

We often wish we had the skills to write understandable and easy to maintain code which will bring us great satisfaction. I consider myself newbie in writing clean code but nevertheless, took the decision to share with you what i have learned so far in an attempt to make better quality software in our beautiful industry.

So, lets start with dirty and clean code examples without wasting your time.

1. Boolean names should sound like true/false questions

Dirty
var open;
var login;

Clean
var isOpen;
var loggedIn;

2. Booleans Comparison

Dirty
if(loggedIn == true) {};

Clean
if(loggedIn) {}; // be implicit

Dirty
if(!isNotLoggedIn);

Clean
if(loggedIn) {}; // stay positive

3. Stay Elegant

Dirty
int registrationFee;
if(isSpeaker){ registrationFee = 10;} else { registrationFee = 50;};

Clean
int registrationFee = isSpeaker ? 10 : 50; // more elegant

Dirty
if(employeeType == "manager") // error prone

Clean
if(employee.Type == EmployeeType.Manager) // intellisense, no typos

4. Avoid Magic Numbers

Dirty
if(status == 2) {} // like magic, few can explain

Clean
if(status == Status.Active) {}

Dirty
if(age > 21) {}

Clean
const int legalDrinkingAge = 21;
if(age > legalDrinkingAge) {}

5. Avoid Large Methods

Strive to write each logic in a separate function. Avoid fat methods that are hard to maintain. Breaking up large methods into smaller methods can increase readability and maintainability. Remember, a method should do one thing and do it well.

6. Return Early Principle

Use a return when it enhances readability... In certain routines, once you know the answer…not returning immediately means that you have to write more code.
[Steve McConnell], “Code Complete”

Dirty

Clean

7. Watch out for Flag Arguments

Watch out for side effects when naming your method:

- ValidateUser() shouldn’t save.
- RegisterUser() shouldn’t send an email.

Dirty
private void SaveUser(User user, bool emailUser)
{
//save user
if(emailUser)
{
//email user
}

Clean
private void SaveUser(User user)
{
//save user
}

private void EmailUser(User user)
{
//email user
}

8. Avoid Comments

This is me to the left during a technical interview @:

Useless Comments as follows:

int i=1; // Set i = 1

var user = new User(); // Instantiate a new user

/// <summary>
/// Default Constructor
/// </summary>
publid User()
{
}

/// <summary>
/// Calculates Total Charges
/// </summary>
private void CalculateTotalCharges()
{
// code here
}

// Assure user's account is not active
if(user.Status == 2)

if(user.Status == Status.Inactive) // Cleaner

Conclusion

Writing clean code brings happiness to software developers. There is nothing more productive than a happy developer.

"Special thanks to Cory House from www.bitnative.com"