isAlphanumeric method

bool isAlphanumeric(
  1. String? s
)

验证是否为字母和数字的组合

Implementation

bool isAlphanumeric(String? s) {
  if (s == null || s.isEmpty) return false;
  const pattern = r'^[a-zA-Z0-9]+$';
  return hasMatch(s, pattern);
}