Object oriented programming (OOP) best practices

In object-oriented programming, we have quite a lot of best practices to apply when writing code. We should make good use of SOLID principles, and object-oriented (OO) design patterns.

The following best practices can be applied on top of SOLID principles, and object-oriented (OO) design patterns.

• Extending Is Better Than Changing
• Avoiding Global State and Non-Deterministic Behaviors
• Avoid Static Classes for Helpers, Utilities, etc
• Separate Creational Logic from Business Logic
• Keep Complexity Level Low
• Keep the method small
• Avoid Too Many If or Switch Statements

The SOLID principles:

• Single Responsibility Principal
• Open/closed principle
• Liskov substitution principle
• Interface segregation principle
• Dependency inversion principle

Other OOP rules:

• “Hollywood principle” which means lower layers should not depend on higher layers.
• “Favor composition over inheritance” – composition allows changing/adding behavior at runtime and is more maintainable
• “Program to an interface, not to the implementation” – always use abstraction as a way of referencing instead of direct coupling to the concrete class