CODEWITHSUNDEEP
c#regexlinq
kame
kame

Reputation: 21960

Linq select with regex

I want to extract the strings like aaa.a1 and aaa.a2 from my list. All this strings contain "aaa.".

How can I combine Regex with Linq?

var inputList = new List<string>() { "bbb aaa.a1 bbb", "ccc aaa.a2 ccc" };

var result = inputList.Where(x => x.Contains(@"aaa.")).Select(x => x ???? ).ToList();

Upvotes: 2

Views: 98

Answers (2)

Michał Turczyn
Michał Turczyn

Reputation: 37367

You could try slight different solution:

var result = inputList
  .Where(i => Regex.Match(i, @"\baaa\.[a-z0-9]+")?.Success)
  // or even
  // .Where(i => Regex.Match(i, @"\ba+\.[a-z0-9]+")?.Success)

Upvotes: 2

Wiktor Stribiżew
Wiktor Stribiżew

Reputation: 626794

You may use

var inputList = new List<string>() { "bbb aaa.a1 bbb", "ccc aaa.a2 ccc" };
var result = inputList
    .Select(i => Regex.Match(i, @"\baaa\.\S+")?.Value)
    .Where(x => !string.IsNullOrEmpty(x))
    .ToList();
foreach (var s in result)
    Console.WriteLine(s);

Output:

aaa.a1
aaa.a2

See C# demo

The Regex.Match(i, @"\baaa\.\S+")?.Value part tries to match the following pattern in each item:

  • \b - a word boundary
  • aaa\. - an aaa. substring
  • \S+ - 1+ non-whitespace chars.

The .Where(x => !string.IsNullOrEmpty(x)) will discard empty items that result from the items with no matching strings.

Upvotes: 3

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