C# Selecting part of string when there is a matching result in part of the string

Question

I have a string which basically looks like this:

/giveaway/host/setup/ref=aga_h_su_dp?_encoding=UTF8&amp;value_id=1484778065

The trick here is that the length of the string can vary and will change... However the part with "value_id=something" always stays same... So the problem that I ran in was that I can do something like this:

var myId = string.SubString(30,45);

to get the value after value_id= /*this one here*/

I'm thinking that this can be solved by regex or some other way, but I'm not too sure how to write such one. Can someone help me out?

@arslanaybars what if there are multiple '=' signs in string ? — User987, Oct 14 '17 at 16:18
@User987 seems like it is a part of an url. So no need for string operations. `var value = HttpUtility.ParseQueryString(HttpUtility.HtmlDecode(input))["value_id"];` — L.B, Oct 14 '17 at 16:24
@User987; take a look at this answer: https://stackoverflow.com/questions/32772271/parse-url-with-regex-c-sharp#32772437 — Casimir et Hippolyte, Oct 14 '17 at 16:26

score 1 · Accepted Answer · answered Oct 14 '17 at 16:20

Could you try this. If your value_id always the last of your string you can use this.

var str = "/giveaway/host/setup/ref=aga_h_su_dp?_encoding=UTF8&amp;value_id=1484778065";

var valueId = str.Split('=').LastOrDefault();

Result : 1484778065

Hope it's help to you

score 0 · Answer 2 · answered Oct 14 '17 at 16:20

0

You can split by 'value_id='

string[] tokens = str.Split(new[] { "value_id=" }, StringSplitOptions.None);

if(tokens.Length>1){
   //parse tokens[1] with the value
}

answered Oct 14 '17 at 16:20

farbiondriven

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good approach. @User987 you can use this also. – arslanaybars Oct 14 '17 at 16:22
@arslanaybars would this work if there are multiple = ? – User987 Oct 14 '17 at 16:24
It will work, but if value_id= is the last. If you have other data after the value you need to separate it, then split again with the separator. – farbiondriven Oct 14 '17 at 16:25

C# Selecting part of string when there is a matching result in part of the string

2 Answers2