“You know you are working on clean code when each routine you read turns out to be pretty much what you expected.” – Ward Cunningham

1. CLEAN CODE
A Summary

2. What is Clean Code?
Easy for
others to
change
Easy for others
to read
Focused on a
particular ‘thing’
Completely
covered by tests

3. Why is Clean Code Important?
 Easy to Read, Easy to Change
The ratio of time spent reading vs. writing is well
over 10:1.
 “You know you are working on clean code
when each routine you read turns out to be
pretty much what you expected.” – Ward
Cunningham

4. Causes of Poor Code Quality
 Inexperience
 Lack of time
 Laziness
 Broken Window Theory

5. Boy Scout Rule
 Leave the campground cleaner
than you found it.

6. Naming Guidelines
 Names should reveal intent
 You may change them repeatedly
 Avoid misleading names
 If you can’t pronounce it, don’t use it
 Longer names > Shorter names
 Avoid prefixes & type encoding

7. Nouns vs Verbs
• Nouns
• Representing
things in the real
world
Classes/Objects
• Verbs
• An action being
taken by the object
Methods

8. Private Constructors & Static
Methods
 Consider using static factory methods to call
parameterized constructors
Student.CreateStudentFirstNameLastName(“Jas
on”, “Rosado”);
vs
new Student(“Jason”, “Rosado”);

9. Rules of Thumb
 Keep methods as short as possible (< 20
lines)
 If statements & loops should only contain
method calls

10. Single Responsibility Principle
Be one thing, do one thing

11. Comments
 Comments describe things that our code
cannot
 int temp = 0; // temperature in celsius
 int temperatureInCelsius= 0;
 Use more descriptive names instead of
comments

12. Bad Comments - Continued
Useless or
Redundant
Comments
Incorrect
Comments
Outdated
Code

13. Good Comments
 Warnings of bad things if
code is deleted
 Future things that need to
be added