What is a SOLID Principal

There was a great convergence of ideas and technology right around 1995. That was when when Bob Martin (fondly called Uncle Bob) first started talking about the “commandment” of Object Oriented Design. It’s also when Java – a then new Object Oriented programming language – was first released.

By the year 2000, Bob Martin had firmly codified his Design Principles and Design Patterns for Object Oriented Development. Somewhere in the early 2000s, Michael Feathers coined the mnemonic SOLID to describe the first 5 principles of OOD – in particular, class design. Each letter also has a 3-letter representation.

 S  SRP  Single Responsibility Principle 
 O  OCP  Open Closed Principle 
 L  LSP  Liskov Substitution Principle 
 I  ISP  Interface Segregation Principle 
 D  DIP  Dependency Inversion Principle 

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