How does PHP handle errors and exceptions?
Interviewer Expectations for this Question
01
Core Competency
Assesses fundamental understanding of PHP conventions, runtime behavior, and memory/performance considerations.
02
Evaluation Criteria
Hiring managers look for precision, avoidance of ambiguous jargon, and ability to explain trade-offs under real production conditions.
Comprehensive Model Answer
Verified Solution
Modern PHP uses exceptions. Throwable is the root interface with two branches: Error (engine-level, e.g. TypeError, DivisionByZeroError) and Exception (application-level).
try {
risky();
} catch (ValidationException $e) {
// handle
} catch (Throwable $e) {
// fallback
error_log($e->getMessage());
} finally {
// always runs
}
Best practice: convert warnings to exceptions with set_error_handler, configure error_reporting(E_ALL), log errors rather than echo them, and never expose stack traces to users in production. Use a global handler via set_exception_handler and register_shutdown_function for fatal errors.
Candidate Response Strategy & Interview Tips
- Start with a concise one-sentence summary: Deliver a direct, confident answer first before expanding into nuances.
- Demonstrate real-world trade-offs: Discuss where this approach excels and when you would avoid it in production systems.
- Discuss complexity & edge cases: Proactively explain time/space complexity or boundary conditions (null values, scale limits).
- Prepare for interviewer follow-ups: Technical hiring panels frequently probe deeper into concurrency, backward compatibility, or alternative libraries.