SOLID Principles

Question 1

SOLID is a

Answer 1

mnemonic for five design principles intended to
make software designs more understandable, flexible and
maintainable.

Question 2

Single Responsibility Principle

Answer 2

A class should have just one reason to change.

Question 3

Open/Closed Principle

Answer 3

Classes should be open for extension but closed for modification.

Question 4

Liskov Substitution Principle

Answer 4

When extending a class, remember that you should be
abletopassobjectsofthesubclassinplaceofobjectsof
the parent class without breaking the client code.

Question 5

Interface Segregation Principle

Answer 5

Clients shouldn’t be forced to depend on methods they
do not use.

Question 6

Low-level classes

Answer 6

implement basic operations such as working with a disk, transferring data over a network, connecting to a
database, etc.

Question 6

Dependency Inversion Principle

Answer 6

High-level classes shouldn’t depend on low-level class-
es. Both should depend on abstractions. Abstractions
shouldn’t depend on details. Details should depend on
abstractions.

Question 7

High-level classes

Answer 7

contain complex business logic that directs
low-level classes to do something.