VB.Net regex matching

Question

Okay, lets say I have a string "The cat in the hat dog", and I know want to regex match cat and dog from the same string.

So I have something like:

Dim myString As String = "The cat in the hat dog"
Dim regex = New Regex("\bcat\b.*\bdog")
Dim match = regex.Match(myString)
If match.Success Then
    Console.WriteLine(match.Value)
End If

The match.Value returns "cat in the hat dog", which is expected.

But what I really need is to just "cat dog" without the other words in the middle, and I'm stuck.

Thanks for any help!

If it helps, the string I'm trying to parse is something like "Game Name 20_03 Starter Pack r6" and I'm trying to pull "20_03 r6" out as version information. Currently using "\b\d{2}_\d{2}\b.\br\d" as my regex string.

Answer 1

You can parenthesize parts of your regular expression to create groups that capture values:

Dim regex As New Regex("\b(cat)\b.*\b(dog)")

Then use match.Groups(1).Value and match.Groups(2).Value.

Answer 2

Your regex would be,

Dim regex = New Regex("\bcat\b|\bdog\b")

This matches the string cat or dog in the input string.

DEMO

For the second string, your regex would be

\b\d{2}_\d{2}\b|r\d

DEMO

Explanation:

• \b Matches the word boundary(ie, matches between a word character and a non-word character).
• \d{2} Matches exactly a two digit number.
• _ Matches a literal underscore symbol.
• \d{2} Matches exactly a two digit number.
• \b Matches the word boundary(ie, matches between a word character and a non-word character).
• | Logical OR operator usually used to combine two regex patterns.this|that, this or that.
• r\d Literal r followed by a single digit.