SOLID Principles



Single responsibility principle
A class should have only a single responsibility (i.e. changes to only one part of the software's specification should be able to affect the specification of the class)

Open/closed principle
software entities should be open for extension, but closed for modification.

Liskov substitution principle
objects in a program should be replaceable with instances of their subtypes without altering the correctness of that program.

Interface segregation principle
Many client-specific interfaces are better than one general-purpose interface.
Subclasses must not be force to implements the methods which are useless for it.

Dependency inversion principle

one should “depend upon abstractions, [not] concretions