How can I select a part from a big string starting in point A and ending in point B

Question

My string is:

[...]
<div class="threads">
<a href="/adgagshsdh_t_54654321654" title="Title 2">
<a href="/adgagsdfdfhsdh_t_44654321654" title="Title 3">
<a href="/adgagsdfhsdh_t_54321654" title="Title 4">
<a href="/adgagsdfhsdfhsdh_t_14654321654" title="Title 5">
[...etc]
</div>
[...]

I want to take everything out except for _t_54654321654 and then after that everything but 54654321654.

Final string should look like this

54654321654

I tried with indexOf but didn't really work.

I tried searching but I didn't know how exactly to describe what I was trying to do.

What's your final out put?? Which portion do u want from it? — Atish Kumar Dipongkor, May 29 '13 at 04:23

score 4 · Accepted Answer · edited Nov 28 '17 at 20:04

string whatYouNeed = "/adgadgdfhdsdfgsadfgdsg_t_54654321654".Split('_').Last();

Or

string whatYouNeed = "<a href=\"/adgadgdfhdsdfgsadfgdsg_t_54654321654\" title=\"Title\">"
    .Split('_')
    .Last()
    .Split(new string[] {"\""},StringSplitOptions.RemoveEmptyEntries)
    .First();

But If you want to work with HTML content you better use Html Agility Pack

Check this question which some what similar to this and by using html agility pack

HtmlDocument htmlDoc = new HtmlDocument();
htmlDoc.Load("test.html");
var link = htmlDoc.DocumentNode
                  .Descendants("a")
                  .First(); // assume it is First link tag what you need

string hrefValue = link.Attributes["href"].Value;
string whatYouNeed = hrefValue.Split('_').Last();

Answers to your comments

but what if I have the source code inside an string and not in a test.html document?

You can load the html as below

HtmlDocument doc = new HtmlDocument();
doc.LoadHtml(html);

Also there's dozens of "<a href"'s with different numbers in them in the source code, I don't need a specific one, just one of them.

var links = htmlDoc.DocumentNode
                      .Descendants("a").ToList();

above will return all the links in the page you can get any item you want like links[1] or links[3] etc ...

this won't work in case op try's to parse the complete html using split..first op should get string out of `href` and then he can use the above code — Anirudha, May 29 '13 at 04:48
Hm... but what if I have the source code inside an string and not in a test.html document? Also there's dozens of " — Gabe Newell, May 29 '13 at 05:06

score 0 · Answer 2 · answered May 29 '13 at 04:28

0

Try it by the sub string method

Like

string sub = mainString.Substring(startPosition, endPosition);

answered May 29 '13 at 04:28

Atish Kumar Dipongkor

10,220
9
49
77

Already tried with substring: "Too many characters in character literal" error – Gabe Newell May 29 '13 at 04:33
U got this error because there are too many string sign("") in your main string. – Atish Kumar Dipongkor May 29 '13 at 04:38
Hm well my whole string is a page source code (html) I'm getting it through string s = reader.ReadToEnd().ToString(); – Gabe Newell May 29 '13 at 04:48

score 0 · Answer 3 · answered May 29 '13 at 04:36

Try:

  Regex rgx = new Regex("^.+?_t_([^\"]+?)\".+?$");
  string result = rgx.Replace(yourString, "$1");

Explanation: It matches characters from the begining of the string using ^ and moves till _t_ and then sub-matches in $1 anything till " and then " and then anything till end $.

The whole string is replaced by the sub-match $1.

score 0 · Answer 4 · answered May 29 '13 at 04:40

0

Try this:

        int index = s.LastIndexOf('_') + 1;
        string t = s.Substring(index, s.Length - index);

answered May 29 '13 at 04:40

KbManu

420
3
7

How can I select a part from a big string starting in point A and ending in point B

4 Answers4