SOLID is a mnemonic acronym for five design principles intended to make software designs more understandable, flexible, and maintainable. The principles are a subset of many principles promoted by American software engineer and instructor Robert C. Martin, first introduced in his 2000 paper Design Principles and Design Patterns.

The SOLID concepts are:

- The Single-responsibility principle: "There should never be more than one reason for a class to change."[5] In other words, every class should have only one responsibility.
- The Open–closed principle: "Software entities ... should be open for extension, but closed for modification."
- The Liskov substitution principle: "Functions that use pointers or references to base classes must be able to use objects of derived classes without knowing it."
- The Interface segregation principle: "Many client-specific interfaces are better than one general-purpose interface."
- The Dependency inversion principle: "Depend upon abstractions, [not] concretions."
- The SOLID acronym was introduced later, around 2004, by Michael Feathers.

Although the SOLID principles apply to any object-oriented design, they can also form a core philosophy for methodologies such as agile development or adaptive software development.


Technical details:

• 50% pre-shrunk cotton, 50% polyester
• Fabric weight: 8.0 oz/yd² (271.25 g/m²)
• Air-jet spun yarn with a soft feel and reduced pilling
• Double-lined hood with matching drawcord
• Quarter-turned body to avoid crease down the middle
• 1 × 1 athletic rib-knit cuffs and waistband with spandex
• Front pouch pocket
• Double-needle stitched collar, shoulders, armholes, cuffs, and hem
• Blank product sourced from Honduras, Mexico, or Nicaragua

Size guide