regex - Regular expression pattern in c#

Question

I need to validate the following string

case 1: 123E

The first three are numeric and then the alphabet.

I have created the following pattern

var pattern = @"^[0-9]{2}[a-zA-Z]{1}"

Is this correct?

question from:https://stackoverflow.com/questions/65841699/regular-expression-pattern-in-c-sharp

Answer 1

Something like that should work: ^[0-9]{3}[a-zA-Z]$ You put {2} for numbers but in your case there are 3 of them so I wrote {3} instead. You don't need to write {1} because [a-zA-Z] is enough to find exacly one letter. I also added endline tag $ to ensure that there are no more symbols after letter.