hex method Null safety

String? hex(
  1. String? value,
  2. {String? message}
)

Check if the value is a valid hexadecimal number.

Implementation

static String? hex(String? value, {String? message}) =>
    value == null || value.isEmpty || validations.isHexadecimal(value) ? null : message ?? 'Please enter a valid hexadecimal';