Code Smells

Question 1

Signs and indicators of future problems/issues in the source code. May cause the program to be hard to understand, maintain and extend.

Answer 1

Code Smells

Question 2

Object-Orientation Abusers:

• method or class is trying to exhibit too many behaviors

Answer 2

Too Many Switch Statements

Question 3

Object-Orientation Abusers:

• fields get their values only under certain circumstances, outside of these circumstances, they’re empty
• refers to a field (variable) that is used only in certain situations or temporarily during execution

Answer 3

Temporary Field

Question 4

Object-Orientation Abusers:

• occurs when a subclass inherits from a parent class but does not use all of the methods and properties of the parent class
• when subclass does not use members inherited from a superclass

Answer 4

Refused Bequest

Question 5

Object-Orientation Abusers:

• closely related classes should share the same interface, so they can be pluggable
• two classes perform identical functions but have different method names

Answer 5

Alternative Classes with Different Interfaces

Question 6

Bloaters:

• a method contains too many lines of code
• methods that are too long are difficult to understand, test, and maintain

Answer 6

Long Method

Question 7

Bloaters:

• a class that contains many fields/methods/lines of code
• classes that are too large are difficult to understand, test, and maintain

Answer 7

Large Class

Question 8

Bloaters:

• occurs when developers overuse primitive data types, such as integers, strings, and booleans, to represent complex domain concepts
• Using primitive instead of creating own classes

Answer 8

Primitive Obsession

Question 9

Bloaters:

• more than three or four parameters for a method
• methods have too many parameters

Answer 9

Long Parameter List

Question 10

Bloaters:

• a group of data that always appear together
• occurs when a group of related variables are passed around together in a clump throughout various parts of the program

Answer 10

Data Clumps

Question 11

Change Preventers:

• same class changed for different reasons
• having to change many unrelated methods when you make changes to a class

Answer 11

Divergent Change

Question 12

Change Preventers:

• Several classes changed for every new feature/code
• making any modifications requires that you make many small changes to many different classes

Answer 12

Shotgun Surgery

Question 13

Change Preventers:

• occurs when an inheritance tree depends on another inheritance tree by composition

Answer 13

Parallel Inheritance Hierarchies

Question 14

Change Preventers:

• code that is too difficult to change without breaking other parts of the codebase. This can make the code difficult to maintain and extend

Answer 14

Rigid Code

Question 15

Dispensables:

• occurs when a method is filled with explanatory comments

Answer 15

Unnecessary Comments

Question 16

Dispensables:

• is code that appears in multiple places in the codebase
• when the same code is repeated multiple times in different parts of the application

Answer 16

Duplicate Code

Question 17

Dispensables:

• occurs when a class is rarely used or has very little functionality
• when a class doesn’t do much

Answer 17

Lazy Class

Question 18

Dispensables:

• occurs when a class is defined primarily to hold data and lacks significant behavior or functionality
• these are simply containers for data used by other classes.

Answer 18

Data Class

Question 19

Dispensables:

• Unused code
• a variable, parameter, field, method or class is no longer used (usually because it’s obsolete)

Answer 19

Dead Code

Question 20

Dispensables:

• occurs when code is written to anticipate future needs that may not actually materialize

Answer 20

Speculative generality

Question 21

Couplers:

• a method accesses the data of another object more than its own data
• when a method excessively accesses the data of another class

Answer 21

Feature Envy

Question 22

Couplers:

• when two classes are constantly accessing each other’s members

Answer 22

Inappropriate Intimacy

Question 23

Couplers:

• occurs when the program asks an object to get another object
• occurs when a class needs to call multiple methods on other classes to get to a particular piece of data or functionality

Answer 23

Message Chains

Question 24

Couplers:

• occurs when a class or an object primarily delegates its work to other classes or objects, forwarding messages without adding any meaningful value of its own

Answer 24

Middle Man