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


I feel kind of dumb posting this when this seems kind of simple and there are tons of questions on strings/characters/regex, but I couldn't find quite what I needed (except in another language: Remove All Text After Certain Point).

I've got the following code:

    public void stringManipulation()
        String filename = "testpage.aspx";
        String currentFullUrl = "http://localhost:2000/somefolder/myrep/test.aspx?q=qvalue";
        String fullUrlWithoutQueryString = currentFullUrl.Replace("?.*", "");
        String urlWithoutPageName = fullUrlWithoutQueryString.Remove(fullUrlWithoutQueryString.Length - filename.Length);

        String expected = "http://localhost:2000/somefolder/myrep/";
        String actual = urlWithoutPageName;
        Assert.AreEqual(expected, actual);

I tried the solution in the question above (hoping the syntax would be the same!) but nope. I want to first remove the queryString which could be any variable length, then remove the page name, which again could be any length.

How can I get the remove the query string from the full URL such that this test passes?

5/23/2017 11:47:13 AM

Accepted Answer

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

string input = "";
int index = input.IndexOf("?");
if (index > 0)
   input = input.Substring(0, index);

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

string input = "";
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("");
string fixedUri = uri.AbsoluteUri.Replace(uri.Query, string.Empty);
4/18/2010 1:31:07 AM

Here's another simple solution. The following code will return everything before the '|' character:

if (path.Contains('|'))
   path = path.Split('|')[0];

In fact, you could have as many separators as you want, but assuming you only have one separation character, here is how you would get everything after the '|':

if (path.Contains('|'))
   path = path.Split('|')[1];

(All I changed in the second piece of code was the index of the array.)


The Uri class is generally your best bet for manipulating Urls.


To remove everything before a specific char, use below.

string1 = string1.Substring(string1.IndexOf('$') + 1);

What this does is, takes everything before the $ char and removes it. Now if you want to remove the items after a character, just change the +1 to a -1 and you are set!

But for a URL, I would use the built in .NET class to take of that.


Request.QueryString helps you to get the parameters and values included within the URL


string http = ""
string customername = Request.QueryString["customername"].ToString();

so the customername variable should be equal to dave



I second Hightechrider: there is a specialized Url class already built for you.

I must also point out, however, that the PHP's replaceAll uses regular expressions for search pattern, which you can do in .NET as well - look at the RegEx class.


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