The document emphasizes the importance of writing clear and maintainable code, highlighting that code is essentially a form of communication among developers. It discusses the significant financial repercussions of poor coding practices, equating them to an annual cost of $85 billion. The content covers best practices for coding, including the necessity of clear naming, simplicity, and the importance of assuming future code maintainers will need to understand and modify the code.

1. Build Solutions,
Not Puzzles
Writing Sensible Code

2. Anis Uddin Ahmad
Head of Software Development
Devnet Limited
http://ajaxray.com/ @ajaxray
/ajaxray
https://gitstat.tophackr.com/ajaxray

3. Code is communication between People

4. Code is communication between People
Time spent by programmers at work
20%
80%
Reading Code
Writing Code

5. Have you ever worked on
other people's code

6. How did you feel?

7. Cost of Bad Code
The opportunity cost
of bad code comes
to $85 billion
annually.
— dev.to

8. Cost of Bad Code
$motivation!--;
$maintainability!--;
$easeOfChange!--;
$debuggingTime!++;
$costOfChange!++;
$costOfNewFeature!++;
Decrease what you
want to have
Increase what you
want to avoid

9. – Martin Fowler
“Any fool can write code that a
computer can understand.
Good programmers write code that
humans can understand.”

10. We Will Not Discuss Today
• KISS - Keep It Simple Stupid
• DRY - Don’t Repeat Yourself
• YAGNI - You Aren’t Gonna Need It
• Composition Over Inheritance
• SOLID Principles
• Code Smells
• UNIX Philosophy
• Law of Demeter
But you should ^ study them anyway…
MUST

11. Never assume…
• I am the ONLY man working on it
• Nothing is going to be added here
• It’s simple, no change will require
• I’ll do the changes if required
• I know how it works, so (whatever)
• I’ll guide the next guy
ONE
MAN
ARMY

12. Rather Presume…
• Someone else is going to work on it
• I may not be there to explain things
• *My boss is going to review it in next performance evolution*

13. “Working” !== “Complete”
Make it work,
Make it right,
Make it fast.
— Kent Beck

14. Make it work,
Make it right,
Make it fast.
— Kent Beck
Presentable & Accurate
• Can it be simpler?
• Are the names intention-revealing?
• Is there any magic/hard coded things?
• Are the functions small enough?
• Is it clear enough for understanding
without my help?
“Working” !== “Complete”

15. class Newsletter {
!// Define properties, constructors etc.
public function circulate(array $connParams, array $apiUrl, DateTime $dt)
{
!// Few lines for collecting news [+12 lines]
$pdo= new PDO($connParams['dsn'], $connParams['user'], $connParams['pass']);
$conditions = ['!!/** a few lines for calculating conditions *!//'];
$newsList = $pdo"->query("!--Multiline Query for getting News!--")"->fetchAll();
!// Collect subscribers from API call to $apiBaseUrl using curl [+7 lines]
!// $result=curl_exec($ch);
$subscribers = json_decode($result, true);
foreach ($newsList as $news) {
!// Check if the news is eligible for newsletter circulation
if ((new DateTime('2020-03-01')) < (new DateTime($news['publishDate']))
"&& $news['print_only'] "!= 1
"&& 'some_other_condition' "== 'whatever') {
$this"->add($news);
}
}
foreach ($subscribers as $user) {
!// Initiate Mailer library as $mailer [+5 lines]
$mailer"->send($user['email'], $this"->getContent());
}
}
!// Other methods…
}

16. class Newsletter {
!// Define properties, constructors etc.
public function circulate(array $connParams, array $apiUrl, DateTime $dt)
{
!// Few lines for collecting news [+12 lines]
$pdo= new PDO($connParams['dsn'], $connParams['user'], $connParams['pass']);
$conditions = ['!!/** a few lines for calculating conditions *!//'];
$newsList = $pdo"->query("!--Multiline Query for getting News!--")"->fetchAll();
!// Collect subscribers from API call to $apiBaseUrl using curl [+7 lines]
!// $result=curl_exec($ch);
$subscribers = json_decode($result, true);
foreach ($newsList as $news) {
!// Check if the new is eligible for newsletter circulation
if ((new DateTime('2020-03-01')) > (new DateTime($news['publishDate']))
"&& $news['print_only'] "!= 1
"&& 'some_other_condition' "== 'whatever') {
$this"->add($news);
}
}
foreach ($subscribers as $user) {
!// Initiate Mailer library as $mailer [+5 lines]
$mailer"->send($user['email'], $this"->getContent());
}
}
!// Other methods…
}
Collecting news from Database - 12 lines
Getting Subscribers from API - 7 lines
Sending Email Newsletter to user - 5 lines
Selecting eligible news for newsletter - 5 lines

17. class Newsletter {
private $newsRepository;
private $subscription;
public function "__construct(NewsRepository $newsRepo, SubscriptionService $subscription)
{
$this"->newsRepository = $newsRepo;
$this"->subscription = $subscription;
}
public function circulate(DateTime $dt)
{
$newsList = $this"->newsRepository"->findForMonth($dt);
$subscribers = $this"->subscription"->getUsers();
foreach ($newsList as $news) {
!// Check if the news is eligible for newsletter circulation
if((new DateTime('2020-03-01')) < (new DateTime($news['publishDate']))
"&& $news['print_only'] "!= 1
"&& 'some_other_condition' "== 'whatever') {
$this"->add($news);
}
}
foreach ($subscribers as $user) {
$this"->sendToUser($user, $this"->getContent());
}
}
private function sendToUser($user, $content){!/* Define sending to User!!... !*/}
!// Other methods…
}

18. class Newsletter {
private $newsRepository;
private $subscription;
public function "__construct(NewsRepository $newsRepo, SubscriptionService $subscription)
{
$this"->newsRepository = $newsRepo;
$this"->subscription = $subscription;
}
public function circulate(DateTime $dt)
{
$newsList = $this"->newsRepository"->findForMonth($dt);
$subscribers = $this"->subscription"->getUsers();
foreach ($newsList as $news) {
!// Check if the news is eligible for newsletter circulation
if((new DateTime('2020-03-01')) < (new DateTime($news['publishDate']))
"&& $news['print_only'] "!= 1
"&& 'some_other_condition' "== 'whatever') {
$this"->add($news);
}
}
foreach ($subscribers as $user) {
$this"->sendToUser($user, $this"->getContent());
}
}
private function sendToUser($user, $content){!/* Define sending to User!!... !*/}
!// Other methods…
}
Collecting news from Database - 12 lines
Getting Subscribers from API - 7 lines
Sending Email Newsletter to user - 5 lines
Dependencies are injected

19. No Mental Mapping
• No “This” means “That”
• Use Domain Terminology
Keep no explanation in YOUR memory,
make it explicit in code
• Self-explanatory names
• Consistent naming - pick one
word per concept

20. public function circulate(DateTime $dt)
{
$newsList = $this"->newsRepository"->findForMonth($dt);
$subscribers = $this"->subscription"->getUsers();
foreach ($newsList as $news) {
!// Check if the new is eligible for newsletter circulation
if((new DateTime('2020-03-01')) < (new DateTime($news['publishDate']))
"&& $news['print_only'] "!= 1
"&& 'some_other_condition' "== 'whatever') {
$this"->add($news);
}
}
!// ....
}
How this $dt is used?
What’s very special abut this day?

21. public function circulate(DateTime $dt)
{
$newsList = $this"->newsRepository"->findForMonth($dt);
$subscribers = $this"->subscription"->getUsers();
foreach ($newsList as $news) {
!// Check if the new is eligible for newsletter circulation
if((new DateTime('2020-03-01')) < (new DateTime($news['publishDate']))
"&& $news['print_only'] "!= 1
"&& 'some_other_condition' "== 'whatever') {
$this"->add($news);
}
}
!// ....
}
public function circulate(DateTime $circulationMonthYear)
{
$newsList = $this"->newsRepository"->findForMonth($circulationMonthYear);
$subscribers = $this"->subscription"->getUsers();
foreach ($newsList as $news) {
!// Check if the news is eligible for newsletter circulation
$moduleStartedDate = new DateTime('2020-03-01');
if(($moduleStartedDate < (new DateTime($news['publishDate']))
"&& $news['print_only'] "!= 1
"&& 'some_other_condition' "== 'whatever') {
$this"->add($news);
}
}
!// ....
}

22. Beware of Copy-Paste Snippets
• Understand every word you’ve
pasted
• Cleanup - keep exactly what
you need
• Change the names for your
context
• Format as per your* coding
style

23. Beware of comments

24. Beware of comments
The best comment is a good name for a method or class.
Purpose of Comment Replace with
Explain a complex expression
Understandable subexpressions
using Extract Variable
Explains a section of code
Extract method with self-explanatory
names
Predefined values (Number/Date/..)
Introduce Constants with purpose-
revealing name

25. foreach ($newsList as $news) {
!// Check if the news is eligible for newsletter circulation
$moduleStartedDate = new DateTime('2020-03-01');
if(($moduleStartedDate < (new DateTime($news['publishDate']))
"&& $news['print_only'] "!= 1
"&& 'some_other_condition' "== 'whatever') {
$this"->add($news);
}
}
1
2
3

26. foreach ($newsList as $news) {
!// Check if the news is eligible for newsletter circulation
$moduleStartedDate = new DateTime('2020-03-01');
if(($moduleStartedDate < (new DateTime($news['publishDate']))
"&& $news['print_only'] "!= 1
"&& 'some_other_condition' "== 'whatever') {
$this"->add($news);
}
}
public function circulate(DateTime $circulationMonth)
{
!// ....
foreach ($newsList as $news) {
if($this"->isEligibleToCirculate($news)) {
$this"->add($news);
}
}
!// ....
}
private function isEligibleToCirculate($news)
{
$moduleStartedDate = new DateTime(self"::MODULE_LAUNCHED_ON);
$newsPublishDate = new DateTime($news['publishDate']);
return $moduleStartedDate < $newsPublishDate
"&& $news['print_only'] "!= 1
"&& 'some_other_condition' "== 'whatever';
}
1
2
3

27. Try Unattended code review
Sign of successful communication

28. Refactoring
Guru
https://refactoring.guru/refactoring

29. Let’s take time to write
sensible code
Be happy by making others happy

30. Questions?