simple regex for a series of numbers and dots. N{3}.N{3}.N{3}.N{3}

Question

I have an ASP.NET 4.0 MVC app in C# and I need to create a regex that will match N{3}.N{3}.N{3}.{N{3} where N{3} is any 1, 2, or 3 digits(0-9) e.g.

    1.1.1.1
    111.111.111.111
    1.111.111.1

I have tried

    @"^[0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}$"

but this matches things I don't want it to like

    111.1.1
    1111.1.1

What am I doing wrong?

I have edited your title. Please see, "[Should questions include “tags” in their titles?](http://meta.stackexchange.com/questions/19190/)", where the consensus is "no, they should not". — John Saunders, May 23 '13 at 20:43

score 6 · Accepted Answer · answered May 23 '13 at 20:10

6

A . in a regular expression means "any character." Therefore if you want to match a literal . you need to escape it, as shown below:

@"^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$"

answered May 23 '13 at 20:10

Sean Bright

2

+1. Should fix it. The regex can probably be shortened to something like `^\d{1,3}(\.\d{1,3}){3}$` – JosephHirn May 23 '13 at 20:16

score 1 · Answer 2 · edited May 23 '17 at 11:43

1

If you're trying to match an IP address, there are some great RexEx expressions here:

edited May 23 '17 at 11:43

Community

answered May 23 '13 at 20:42

Daniel Flippance

2 Answers2