Bassirou GUEYE

LoD
According to the law of Demeter, classes should know about and interact with a few other classes as possible. It is used to loosen the coupling by limiting class interaction with other classes to provide stability as tighter coupling makes the program difficult to maintain.

SOLID Principles

• Single Responsibility Principle

Keeping components laser focused

• Open-Closed Principle

Evolving code without modifying existing components

• Liskov Substitution Principle

Generating correct relationships between types

• Interface Segregation Principle

Modularizing abstractions

• Dependency Inversion Principle

Decoupling components

Advantages of Immutability:

• Immutability makes programs less complicated
• Immutable objects are thread-safe
• Collections such as HashMap and HashSet expect immutability
• Immutable objects can be safely be shared and reused

Functional Programming:
A programming paradigm that treats computation as the
evaluation of mathematical functions and avoids
changing-state and mutable data.

Java

An Optional is a container that can either
contain a value or be empty

"I call it my billion-dollar mistake. It was
the invention of the null reference
in 1965."
Sir Tony Hoare - 2009