Form Validation in Flutter

Form Validation in Flutter — a practical guide to Flutter form validation with clear examples you can reuse in real projects.

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Short description

Call `formKey.currentState!.validate()` before submit; keep validators pure and clear.

Email validator

String? emailValidator(String? v) {
  if (v == null || v.isEmpty) return 'Required';
  if (!v.contains('@')) return 'Invalid email';
  return null;
}