Assertion is a statement in code that checks if a condition is true. It helps ensure software correctness. Key aspects include:
Purpose:
- Verify expected program behaviour
- Detect errors early in development
- Document assumptions in code
Implementation:
- Boolean expression: Evaluates true or false
- Typically uses assert keyword in many languages
- Throws an exception if the condition is false
Usage:
- Input validation: Check if the parameters are valid
- State verification: Ensure object state is correct
- Postcondition checks: Verify results after operations
Benefits:
- Catch bugs early in development
- Improve code readability
- Serve as live documentation
Best Practices:
- Use for developer errors, not user input validation
- Keep assertions simple and fast
- Disable in-production for performance
Assertions help maintain software quality by catching unexpected behaviour quickly.