creditcard constant
Pattern
const creditcard
Credit/Debit Card
Implementation
static const Pattern creditcard =
r"^(?:3[47]\d{2}([\- ]?)\d{6}\1\d{5}|(?:4\d{3}|5[1-5]\d{2}|6011)([\- ]?)\d{4}\2\d{4}\2\d{4})$";