isEmailValid method
Returns true
if email matches the pattern
Implementation
bool isEmailValid({String? regex}) {
final defaultRegex =
r"^[a-zA-Z0-9.a-zA-Z0-9.!#$%&'*+-/=?^_`{|}~]+@[a-zA-Z0-9]+\.[a-zA-Z]+";
return isNullOrEmpty.not()
? RegExp(regex ?? defaultRegex).hasMatch(this!)
: false;
}