C＃ - Regex匹配整个单词

Question

I need to match all the whole words containing a given a string.

string s = "ABC.MYTESTING
XYZ.YOUTESTED
ANY.TESTING";

Regex r = new Regex("(?<TM>[!\..]*TEST.*)", ...);
MatchCollection mc = r.Matches(s);

I need the result to be:

MYTESTING
YOUTESTED
TESTING

But I get:

TESTING
TESTED
.TESTING

How do I achieve this with Regular expressions.

Edit: Extended sample string.

Answer 1

If you were looking for all words including 'TEST', you should use

@"(?<TM>\w*TEST\w*)"

\\w includes word characters and is short for [A-Za-z0-9_]

Answer 2

保持简单：为什么不尝试\\w*TEST\\w*作为匹配模式。

Answer 3

I get the results you are expecting with the following:

string s = @"ABC.MYTESTING
XYZ.YOUTESTED
ANY.TESTING";

var m = Regex.Matches(s, @"(\w*TEST\w*)", RegexOptions.IgnoreCase);

Answer 4

Try using \\b . It's the regex flag for a non-word delimiter. If you wanted to match both words you could use:

/\b[a-z]+\b/i

BTW, .net doesn't need the surrounding / , and the i is just a case-insensitive match flag.

.NET Alternative:

var re = new Regex(@"\b[a-z]+\b", RegexOptions.IgnoreCase);

Answer 5

Using Groups I think you can achieve it.

        string s = @"ABC.TESTING
        XYZ.TESTED";
        Regex r = new Regex(@"(?<TM>[!\..]*(?<test>TEST.*))", RegexOptions.Multiline);
        var mc= r.Matches(s);
        foreach (Match match in mc)
        {
            Console.WriteLine(match.Groups["test"]);
        }

Works exactly like you want.

BTW, your regular expression pattern should be a verbatim string ( @"")

Answer 6

Regex r = new Regex(@"(?<TM>[^.]*TEST.*)", RegexOptions.IgnoreCase);

First, as @manojlds said, you should use verbatim strings for regexes whenever possible. Otherwise you'll have to use two backslashes in most of your regex escape sequences, not just one (eg [!\\\\..]* ).

Second, if you want to match anything but a dot, that part of the regex should be [^.]* . ^ is the metacharacter that inverts the character class, not ! , and . has no special meaning in that context, so it doesn't need to be escaped. But you should probably use \\w* instead, or even [AZ]* , depending on what exactly you mean by "word". [!\\..] matches ! or . .

Regex r = new Regex(@"(?<TM>[A-Z]*TEST[A-Z]*)", RegexOptions.IgnoreCase);

That way you don't need to bother with word boundaries, though they don't hurt:

Regex r = new Regex(@"(?<TM>\b[A-Z]*TEST[A-Z]*\b)", RegexOptions.IgnoreCase);

Finally, if you're always taking the whole match anyway, you don't need to use a capturing group:

Regex r = new Regex(@"\b[A-Z]*TEST[A-Z]*\b", RegexOptions.IgnoreCase);

The matched text will be available via Match's Value property.