C# regex to match string

Question

I'm currently having difficulty matching strings with my regex. The objective is to match:

• One or two letters
• One, two or three numbers
• Zero or one asterisk

Such as U21, F305 and H12*. The regex that I'm using is:

\D{1,2}\d{1,3}\*?

However, it's been matching strings like:

• 3.0L
• 6HBW20
• 3/8"
• Y1015

I'm not too bright with regex, but this is holding me from completing my project. Can anyone help me out?

Thank you.

Answer 1

Try using /^[a-zA-Z]{1,2}\d{1,3}\*?$/

The anchors ^ and $ are useful to make sure that you match exactly the pattern you intend. Read up on them :)

Answer 2

You need to anchor your match. ^ anchors the match to start of line; $ drops anchor at end of line.

Try this regular expression

@"^[\p{L}]{1,2}\d{1,3}[*]?$"

Answer 3

\D matches any non-digit, which is a much larger set than just letters (basically everything else, including periods, slashes, etc). Try using [a-zA-Z]{1,2} to match 1 or 2 letters.

[a-zA-Z]{1,2}\d{1,3}\*?