Remove characters after specific character in string, then remove substring?

To remove everything before the first /

input = input.Substring(input.IndexOf("/"));

To remove everything after the first /

input = input.Substring(0, input.IndexOf("/") + 1);

To remove everything before the last /

input = input.Substring(input.LastIndexOf("/"));

To remove everything after the last /

input = input.Substring(0, input.LastIndexOf("/") + 1);

An even more simpler solution for removing characters after a specified char is to use the String.Remove() method as follows:

To remove everything after the first /

input = input.Remove(input.IndexOf("/") + 1);

To remove everything after the last /

input = input.Remove(input.LastIndexOf("/") + 1);

For string manipulation, if you just want to kill everything after the ?, you can do this

string input = "http://www.somesite.com/somepage.aspx?whatever";
int index = input.IndexOf("?");
if (index >= 0)
   input = input.Substring(0, index);

Edit: If everything after the last slash, do something like

string input = "http://www.somesite.com/somepage.aspx?whatever";
int index = input.LastIndexOf("/");
if (index >= 0)
    input = input.Substring(0, index); // or index + 1 to keep slash

Alternately, since you're working with a URL, you can do something with it like this code

System.Uri uri = new Uri("http://www.somesite.com/what/test.aspx?hello=1");
string fixedUri = uri.AbsoluteUri.Replace(uri.Query, string.Empty);