Add prefix string in URL string

May 5, 2022

User input the url string in a textbox and I need to add a string "cmd" if not available .

Please suggest how to achieve this,

string cmdUrl = AddPrefix("https://google.com");

static string AddPrefix(string inputUrl)
{
   return formattedUrl;// want to return https://cmd.google.com if the string cmd not added already in url
}

>Solution :

First, you can parse your url using var parsedUrl = new Uri(inputUrl).
Then check if the host includes your substring like this: parsedUrl.Host.StartsWith("cmd")
If it does, return your original url else build your new one: $"{parsedUrl.Scheme}://cmd.{parsedUrl.Host}{parsedUrl.PathAndQuery}"