What does the 'I' in SOLID stand for?

What does the 'I' in SOLID stand for?

• A. Interface Design Principle
• B. Inversion of Dependencies Principle
• C. Interface Segregation Principle
• D. Independent Modules Principle

Answer: (C)

The I in SOLID stands for Interface Segregation Principle. It says you should design small, client-specific interfaces so that nothing forces a client to depend on methods it doesn’t use. By splitting fat interfaces into focused ones, you keep implementations lean and decoupled from unnecessary features, making changes safer and evolution easier. A practical example is having separate interfaces for printing and scanning instead of one large interface that includes both capabilities; classes that only print won’t be tied to scanning methods. The other options don’t match the standard terminology here and describe different ideas, so only Interface Segregation captures the need to keep interfaces narrow and task-specific.

The I in SOLID stands for Interface Segregation Principle. It says you should design small, client-specific interfaces so that nothing forces a client to depend on methods it doesn’t use. By splitting fat interfaces into focused ones, you keep implementations lean and decoupled from unnecessary features, making changes safer and evolution easier. A practical example is having separate interfaces for printing and scanning instead of one large interface that includes both capabilities; classes that only print won’t be tied to scanning methods. The other options don’t match the standard terminology here and describe different ideas, so only Interface Segregation captures the need to keep interfaces narrow and task-specific.