Which best describes defensive coding?

• A. A coding approach where code not needed is removed and errors are handled gracefully
• B. A method to accelerate performance by avoiding error checks
• C. A strategy to encrypt all data by default
• D. A technique to deploy code to production quickly

Answer: (A)

Defensive coding is about building software that can cope with unexpected inputs and conditions without crashing. The best description is the idea of removing unnecessary complexity while ensuring errors are detected and handled gracefully, so the system remains stable and behaves predictably when something goes wrong. This means validating inputs, checking for nulls, catching and handling exceptions, and providing safe defaults or failover paths. It’s not primarily about speeding up performance by skipping checks, nor about encrypting all data by default, nor about rushing deployments—those touch on security, performance trade-offs, or process speed rather than robust error handling and resilience.