c# - Regex for integer in the word not failing properly -

i trying create regex match 1 string format. strings this

 a3476,texta b5628,textb a9871,textc 

the first character should either 'a' or 'b' , follow integer number should 4 chars in length , followed ','. after comma 3 words repeate either 'texta' or 'textb' or 'textb'.

i have tried regex

 (a|b)(\d{4})(,)(texta|textb|textc) 

when add alphabet in integer number or integer number greater 4 chars in length string match should fail not failing.

suppose if string this

 a653k7876,texta 

i getting result 7876,texta. result missing character 'a' , reading integer end. intention should fail.

your regex fine, except should indicate should start , end match. ^ special character indicates start of line or string, , $ end. so, try instead:

^(a|b)(\d{4})(,)(texta|textb|textc)$ 

make sure specify regexoptions.multiline when creating regex object make work.