Discover how guard clauses in C# simplify validation and error handling. Learn to write fail-fast code, avoid nested conditionals, and keep business logic clean with modern language features and reusable helpers.
Quick Reference Table Feature Abstract Class Interface When to Use Inheritance Single only Multiple allowed Abstract: shared logic; Interface: contracts Implementation Can provide Contract only Abstract: code reuse; Interface: flexibility Constructors Supported Not allowed Abstract: initialization; Interface: pure contracts State/Fields Yes No Abstract: data sharing; Interface: behavior only Performance Slightly faster Virtual dispatch Abstract: hot paths; Interface: most scenarios Testing Can be difficult Easy with mocks Abstract: integration tests; Interface: unit tests Common Pitfalls: ...