String comparison with Wildcard search in c#
10,328
I suggest converting SQL-LIKE into regular expression:
private static string LikeToRegular(string value) {
return "^" + Regex.Escape(value).Replace("_", ".").Replace("%", ".*") + "$";
}
And then use Regex
as usual:
string like = "%A%C%";
string source = "A B C";
if (Regex.IsMatch(source, LikeToRegular(like))) {
Console.Write("Matched");
}
You can even implement an extension method if you want:
public class StringExtensions {
public static bool ContainsLike(this string source, string like) {
if (string.IsNullOrEmpty(source))
return false; // or throw exception if source == null
else if (string.IsNullOrEmpty(like))
return false; // or throw exception if like == null
return Regex.IsMatch(
source,
"^" + Regex.Escape(like).Replace("_", ".").Replace("%", ".*") + "$");
}
}
So you can put
string like = "%A%C%";
string source = "A B C";
if (source.ContainsLike(source, like)) {
Console.Write("Matched");
}
Author by
Ehsan Ullah Nazir
Updated on June 14, 2022Comments
-
Ehsan Ullah Nazir almost 2 years
I have two strings for comparison
String Str1 = "A C"; String Str2 = "A B C"; Str2.Contains(Str1); //It will return False ,Contains append % at Start and End of string //Replace space with % Str1 = "%A%C%"; Str2 = "%A%B%C%"; Str2.Contains(Str1); //Want it to return True ,
We do have
Contains,StartsWith,EndsWith
methods for comparison, But what my requirement is , if we compare str2 and str3 , it should return True , as it lies in Str2.Can we achive such behaviour in C# ?I have done this in SQL but not getting some useful at C#.Any regex etc ?