In computer programming, SOLID (Single responsibility, Open-closed, Liskov substitution, Interface segregation and Dependency inversion) is a mnemonicacronym introduced by Michael Feathers for the "first five principles" named by Robert C. Martin[1][2] in the early 2000s[3] that stands for five basic principles of object-oriented programming and design. The principles, when applied together, intend to make it more likely that a programmer will create a system that is easy to maintain and extend over time.[3] The principles of SOLID are guidelines that can be applied while working on software to remove code smells by causing the programmer to refactor the software's source code until it is both legible and extensible. It is part of an overall strategy of agile and adaptive programming.[3]
a class should have only a single responsibility (i.e. only one potential change in the software's specification should be able to affect the specification of the class)
“objects in a program should be replaceable with instances of their subtypes without altering the correctness of that program.” See also design by contract.
^“Principles Of OOD”, Robert C. Martin (“Uncle BOB”), butunclebob.com, Last verified 2014-07-17. (Note the reference to “the first five principles”, though the acronym is not used in this article.) Dates back to at least 2003.
^ abc“SOLID Object-Oriented Design”, Sandi Metz (Duke University), Talk given at the 2009 Gotham Ruby Conference in May, 2009. Last verified 2009-01-15.
