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Get INT value between 2 matching chars

I have a string that I need to separate the product ID from, is this format
shop:?id:556:token:bmgwcGJxZEpnK2RqemhaKzdBYWZjbTVZN0xaOXh5L3pmdDBFZjQrWVVES1pmYVBXVVB6SlFhejBsNndnaHNsUA==
I need to get 556 out of there, and in the case of say 2658 etc also possible.
First index ":" I think
str.Substring(str.LastIndexOf(':') + 1);
But then I dont know how to just break after the match, regex better? any help apprecaited
EDIT
These do the exact same thing, seperating the first numbers out
LINQ:
var test = new string(str.Substring(str.IndexOfAny("0123456789".ToCharArray())).TakeWhile(char.IsDigit).ToArray());
Reggex:
var test = Regex.Match(str, #"\d+").Value;
So bears the question, which is better approach?

If the string format is fixed, use the Split function
string str = "shop:?id:556:token:bmgwcGJxZEpnK2RqemhaKzdBYWZjbTVZN0xaOXh5L3pmdDBFZjQrWVVES1pmYVBXVVB6SlFhejBsNndnaHNsUA==";
int id = Convert.ToInt32(str.Split(':')[2]);
Console.WriteLine(id);

I'd probably use Regex:
var id = Regex.Match(input, #"\?id:(?<x>\d+)").Groups["x"].Value
Decoded, that Regex means "literally match ?id: then start a capturing group called x and capture one or more digits into it"
The returned Match will have a Groups property that we index by x and retrieve the value
If you want it as an int you can int.Parse the result-you won't need a TryParse because the Regex will have only matched digits
If the format of the string is fixed then this would work:
input[9..input.IndexOf(':',10)];
And it would be more performant than Regex or Split
If you wanted a substring that works with a format change, perhaps:
var x = input.IndexOf("?id:") + 4;
var id = input[x..input.IndexOf(':',x+1)];

This will work even if the order of items changes.
string original = "shop:?id:556:token:bmgwcGJxZEpnK2RqemhaKzdBYWZjbTVZN0xaOXh5L3pmdDBFZjQrWVVES1pmYVBXVVB6SlFhejBsNndnaHNsUA==";
string startWithId = original.Substring(original.IndexOf("id:") + 3);
string onlyId = startWithId.Split(':')[0];
Console.WriteLine(onlyId);

C# Extract part of the string that starts with specific letters

I have a string which I extract from an HTML document like this:
var elas = htmlDoc.DocumentNode.SelectSingleNode("//a[#class='a-size-small a-link-normal a-text-normal']");
if (elas != null)
{
//
_extractedString = elas.Attributes["href"].Value;
}
The HREF attribute contains this part of the string:
gp/offer-listing/B002755TC0/
And I'm trying to extract the B002755TC0 value, but the problem here is that the string will vary by its length and I cannot simply use Substring method that C# offers to extract that value...
Instead I was thinking if there's a clever way to do this, to perhaps a match beginning of the string with what I search?
For example I know for a fact that each href has this structure like I've shown, So I would simply match these keywords:
offer-listing/
So I would find this keyword and start extracting the part of the string B002755TC0 until the next " / " sign ?
Can someone help me out with this ?

This is a perfect job for a regular expression :
string text = "gp/offer-listing/B002755TC0/";
Regex pattern = new Regex(#"offer-listing/(\w+)/");
Match match = pattern.Match(text);
string whatYouAreLookingFor = match.Groups[1].Value;
Explanation : we just match the exact pattern you need.
'offer-listing/'
followed by any combination of (at least one) 'word characters' (letters, digits, hyphen, etc...),
followed by a slash.
The parenthesis () mean 'capture this group' (so we can extract it later with match.Groups[1]).
EDIT: if you want to extract also from this : /dp/B01KRHBT9Q/
Then you could use this pattern :
Regex pattern = new Regex(#"/(\w+)/$");
which will match both this string and the previous. The $ stands for the end of the string, so this literally means :
capture the characters in between the last two slashes of the string

Though there is already an accepted answer, I thought of sharing another solution, without using Regex. Just find the position of your pattern in the input + it's lenght, so the wanted text will be the next character. to find the end, search for the first "/" after the begining of the wanted text:
string input = "gp/offer-listing/B002755TC0/";
string pat = "offer-listing/";
int begining = input.IndexOf(pat)+pat.Length;
int end = input.IndexOf("/",begining);
string result = input.Substring(begining,end-begining);
If your desired output is always the last piece, you could also use split and get the last non-empty piece:
string result2 = input.Split(new string[]{"/"},StringSplitOptions.RemoveEmptyEntries)
.ToList().Last();

Extract all values between { dynamic } and place in a string array

I need to extract all words between { } brackets and place in a string array.
The problem is that the text between the brackets is dynamic.
For example:
Hi {name}, thanks for visiting {site}
In this text i want to get name and site words place in a array.
Thanks!

Solution : you can use Substring() function to retrieve the part of the string.
Syntax: Substring(int startindex,int length);
Steps:
1. you need to send the starting index(1) of { to Substring() function as first parameter.
2. you need to send the length of string to be retrieved that means index(2) of } in the form of length (index2-index1) to Substring() function as second parameter.
Try this:
String middlevalue="";
String str = "thanks for visiting {site}";
int index1= str.IndexOf("{");
index1++;
int index2=str.IndexOf("}");
if(index1!=-1 && index2!=-1)
middlevalue=str.Substring(index1, (index2 - index1)));
Output:
middlevalue contains -> site

Regex should work for you, note that all the words between {...} should not contain any {...}.
var items = Regex.Matches(input, "\{[^{]+\}").Cast<Match>()
.Select(m=>m.Value.Trim('{','}')).ToArray();

Adding to King's answer, this will help you retrieve just the keys without surrounding brackets.
Regex.Matches(input, #"\{(?<Value>[^{]+)\}").Cast<Match>()
.Select(m=>m.Groups["Value"].Value).ToArray();

Try this:
var regex = #"(?<=\{)[^}]*(?=\})";
var text = "Hello my name is {James}";
var matches = Regex.Matches(text, regex);

How to split string between different chars

I am having trouble splitting a string. I want to split only the words between 2 different chars:
string text = "the dog :is very# cute";
How can I grab only the words, is very, between the : and # chars?

You can use String.Split() method with params char[];
Returns a string array that contains the substrings in this instance
that are delimited by elements of a specified Unicode character array.
string text = "the dog :is very# cute";
string str = text.Split(':', '#')[1]; // [1] means it selects second part of your what you split parts of your string. (Zero based)
Console.WriteLine(str);
Here is a DEMO.
You can use it any number of you want.

That's not really a split at all, so using Split would create a bunch of strings that you don't want to use. Simply get the index of the characters, and use SubString:
int startIndex = text.IndexOf(':');
int endIndex = test.IndexOf('#', startIndex);
string very = text.SubString(startIndex, endIndex - startIndex - 1);

use this code
var varable = text.Split(':', '#')[1];

Regex regex = new Regex(":(.+?)#");
Console.WriteLine(regex.Match("the dog :is very# cute").Groups[1].Value);

One of the overloads of string.Split takes a params char[] - you can use any number of characters to split on:
string isVery = text.Split(':', '#')[1];
Note that I am using that overload and am taking the second item from the returned array.
However, as #Guffa noted in his answer, what you are doing is not really a split, but extracting a specific sub string, so using his approach may be better.

Does this help:
[Test]
public void split()
{
string text = "the dog :is very# cute" ;
// how can i grab only the words:"is very" using the (: #) chars.
var actual = text.Split(new [] {':', '#'});
Assert.AreEqual("is very", actual[1]);
}

Use String.IndexOf and String.Substring
string text = "the dog :is very# cute" ;
int colon = text.IndexOf(':') + 1;
int hash = text.IndexOf('#', colon);
string result = text.Substring(colon , hash - colon);

I would just use string.Split twice. Get the string to the right of the first separator. Then, using the result, get the string to the left of second separator.
string text = "the dog :is very# cute";
string result = text.Split(":")[1] // is very# cute";
.Split("#")[0]; // is very
It avoids playing around with indexes and regex which makes it more readable IMO.

Looking for the simplest way to extract tow strings from another in C#

I have the following strings:
string a = "1. testdata";
string b = "12. testdata xxx";
What I would like is to be able to extract the number into one string and the characters following the number into another. I tried using .IndexOf(".") and then remove, trim and
substrings. If possible I would like to find something simpler as I have this to do in a
lot of parts of my code.

if the format is always the same you could do:
a.Split('.');

Proposed solutions so far are not correct.
First, after Split('.') or Split(".") you will have space in the beginning of second substring.
Second, if you have more than one dot - you'll have to do something yet after the split.
More robust solution is below:
string a = "11. Test string. With dots.";
var res = a.Split(new[] {". "}, 2, StringSplitOptions.None);
string number = res[0];
string val = res[1];
Argument 2 specifies maximum number of strings to return. Thus when you have several dots - it will make a split only at the first.

string[]list = a.Split(".");
string numbers = list[0];
string chars = list[1];