LWCBeginnerformsvalidation
How does LWC handle forms and validation?
Real World Scenario
Users submit incomplete custom forms. You describe client-side validation approach.
Expected Answer
• Use lightning-input required and pattern attributes for basic HTML5 validation
• Query lightning-input components and call reportValidity() before submit
• Combine client validation with Apex server validation—never trust client alone
• lightning-record-edit-form handles standard object validation rules automatically
• Show field-level errors with setCustomValidity for custom messages
Follow-Up Questions & Answers
Click to expand — each follow-up includes a direct, interview-ready answer
Apex throws AuraHandledException with message; display in toast or inline. Map errors to fields when possible.
Architect Perspective
Client + server validation duo—security-aware junior answer in one breath.