In this article I want to briefly go through SOLID principles (acronym that stands for five basic principles of object-oriented programming and design) supplying each of them with real-world visual examples to make those principles more understandable, readable and memorisable.
So let’s move on!
[a.k.a SRP] A class should have only a single responsibility. Only one potential change in the software’s specification should be able to affect the specification of the class.
[a.k.a OCP] Software entities should be open for EXTENSION, but closed for MODIFICATION. Allow behaviour to be extended without modifying the source-code.
[a.k.a. LSP] Objects in a program should be replaceable with instances of their subtypes without altering the correctness of that program.
[a.k.a. ISP] Many client-specific interfaces are better than one general-purpose interface. No client should be forced to depend on methods it does not use.
[a.k.a. DIP] One should depend upon abstractions, not concretions.
- High-level modules should not depend on low-level modules. Both should depend on abstractions.
- Abstractions should not depend on details. Details should depend on abstractions.
The plug doesn’t care which type of wire it uses, it just needs wires that conduct electricity.
I hope these illustration have been useful for you :)