Let us say our input string is −

string input = "https://example.com/new.html";

现在我们需要检查www或非www链接。为此，在C#中使用if语句−

if (input.StartsWith("https://www.example.com") || input.StartsWith("https://example.com")) {
}

Example

You can try to run the following code to check for URL in a string.

Live Demo

using System;
class Demo {
   static void Main() {
      string input = "https://example.com/new.html";
      // See if input matches one of these starts.
      if (input.StartsWith("https://www.example.com") || input.StartsWith("https://example.com")) {
         Console.WriteLine(true);
      }
   }
}

输出

True