SOLID Principles

Question 1

S

Answer 1

Single Responsibility Principle
A class should have one and only one reason to change.

Question 2

O

Answer 2

Open/Closed Principle

Software entities should be open for extension but closed for modification.

Question 3

L

Answer 3

Liskov Substitution Principle

Subtypes must be substitutable for their base types.

Question 4

I

Answer 4

Interface Segregation Principle
The dependency of one class to another one should depend on the smallest possible interface.
- Clients should not be forced to implement interfaces they don't use.
- Instead of one fat interface many small interfaces are preferred based on groups of methods, each one serving one submodule.

Question 5

D

Answer 5

Dependency Inversion Principle

Depend upon abstractions (interfaces), not concrete classes.