Coupling

Composition vs Inheritance in OOP

Inheritance models an "is-a" relationship where a class derives from a parent, while composition models a "has-a" relationship where a class is built from othe…

What is Coupling and Cohesion in OOP?

Coupling measures how dependent one module or class is on another, while cohesion measures how strongly the responsibilities inside a single module belong toge…

What is the Interface Segregation Principle?

The Interface Segregation Principle (the 'I' in SOLID) states that no client should be forced to depend on methods it does not use, so large interfaces should…

What is the Law of Demeter?

The Law of Demeter, also called the principle of least knowledge, states that a method should only call methods on itself, its own fields, its parameters, or o…

What is the God Object Anti-Pattern?

A God Object is a class that has grown to know or do far too much — it centralizes unrelated state and behavior from across the system, violating the single re…

What is Spaghetti Code?

Spaghetti code is source code with a tangled, unstructured control flow and object structure — jumps, deep conditionals, and unclear dependencies between class…

What is the Circular Dependency Anti-Pattern?

A circular dependency is a design flaw where two or more classes (or modules) depend directly on each other, either mutually referencing one another or forming…

What is a Tightly Coupled System?

A tightly coupled system is one where classes or modules depend heavily on each other’s concrete internal details, so a change in one nearly always forces a ch…

What is a Loosely Coupled System?

A loosely coupled system is one where classes interact through stable abstractions like interfaces rather than concrete implementations, so a class can be swap…

What is the Composite Reuse Principle?

The Composite Reuse Principle states that classes should achieve code reuse through composition — holding references to other objects and delegating to them —…

What is a Fat Interface in OOP?

A fat interface is an interface that declares too many unrelated methods, forcing implementing classes to provide (or stub out) behavior they don’t actually ne…

Header Interface vs Role Interface

A header interface exposes every public method of a single concrete class as one large interface mirroring that class, while a role interface is a small, clien…