Why doesn't the regex work?

Question

.NET

string pattern = @"\d{3}(-XX-)\d{2}(/)(?:\d{5}|\d{7})";
            string value1 = @"111-XX-99/12345";
            string value2 = @"111-XX-99/1234567";
            var rez1 = Regex.IsMatch(value1, pattern);
            var rez2 = Regex.IsMatch(value2, pattern);

IsMatch returns true, but if, for example, you write value = @"1111-XX-99/12345678"; it still returns true. How can I fix the expression so that it only skips 5 or 7 digits after the / ?

Answer 1

try
\d{3}(-XX-)\d{2}(/)(?:\d{5}|\d{7})\b