SOLID-PHP

Single responsibility principle (SPR)

• It's about reducing class coupling by splitting and giving each class just one function.

• Each software module should have one and only one reason to change.
  Uncle Bob

  
  

Open/closed principle (OCP)

• We must ensure that each action or responsibility is in the correct class through interfaces, access modifiers and getters/setters we can achieve this goal.

• Software entities (classes, modules, functions, etc.) must be open for extension but closed for modification.
  Bertrand Meyer

Liskov substitution principle (LSP)

• Attest to which method is being subtyped/ extended, so that there are no implementation conflicts.

• liskov's substitution principle, a base class must be able to be replaced by its child classes anywhere in the code

  
  

The interface segregation principle: (ISP)

• Clients should not be forced to depend upon interfaces that they do not use.
  
  

dependency inversion principle:

• Depend upon abstractions, [not] concretions.