c# - match pattern for startswith -
i want regex match in c# check whether string starts part of pattern. if pattern "abc...ghi" valid strings can in format "a","ab","abcdef","abcxyxghi" this sample code. regex has in pattern make work string pattern = "abc...ghi" code = "a" //valid code = "abc" valid code = "abcde" //valid code = "abcxxx" //valid code = "abcxxxghi" //valid code = "abcxxxghiaa" //invalid code = "b" //invalid regex.ismatch(code, pattern) you can use ? , make optional part of regexp. final regexp string be a(b(c(.(.(.(g(h(i?)?)?)?)?)?)?)?)? the final string quite messy can create automatically the visualization of above regexp here http://www.regexper.com/#a(b(c(.(.(.(g(h(i%3f)%3f)%3f)%3f)%3f)%3f)%3f)%3f)%3f