split number from a string in c#

Question

I have a string in c# like this :

{ name: "Phai dấu cuộc tình", mp3: "audio\\16\\Phai dau cuoc tinh.mp3"},{ name: "Caravan of life", mp3: "audio\\4\\Caravan of life.mp3"},{ name: "I'm Forbidden", mp3: "audio\\11\\I'm Forbidden.mp3"},{ name: "Cause i love you", mp3: "audio\\6\\Cause i love you.mp3"},{ name: "Chỉ là giấc mơ", mp3: "audio\\8\\Chi la giac mo.mp3"},{ name: "Lột xác", mp3: "audio\\12\\Lot xac.mp3"}

I want to get the number between "\\" to a new string. For example, the result will be : 16;4;11;6;8;12. Any help would be great.

Can you tell us what you have done already? Have you gone to regex tutorials. there are a ton online — Justin Pihony, Dec 12 '13 at 16:11
As @LSaks says, you've got a set of [json](http://json.org/) data. Questions like [this one](http://stackoverflow.com/questions/6620165/how-to-parse-json-in-c) will get you started. Once you've parsed the json, you can then easily use a regular expression to capture what's between the **decoded** `audio\16\Phai...` etc. — brandonscript, Dec 12 '13 at 16:13
i tried function split in c#, it worked but i think it's not the good solution for it. — Anh Nguyen, Dec 12 '13 at 16:14
Parse that string in an JSON Object. After that, your job is pretty easy. — everton, Dec 12 '13 at 16:15
Although the data looks like JSON, why does OP need a JSON parser for this? Couldn't he do it with just `Regex`? — Shiva, Dec 12 '13 at 16:15
@Shiva *really*? http://cstheory.stackexchange.com/questions/3987/is-json-a-regular-language yes you CAN do it with regex, but it's not a good idea, and it's going to process slower than actually parsing it with a parser. — brandonscript, Dec 12 '13 at 16:16
@r3mus I dispute the claim that a regex engine that creates several result objects is slower that a JSON parser that creates a whole tree. Citation required, sir. — Gusdor, Dec 12 '13 at 16:18
Thanks @r3mus Not sure why you linked to that `cstheory` question and also threw in some attitude. My question was a sincere one. More importantly, the answer with most upvotes is a `Regex` answer ;) — Shiva, Dec 12 '13 at 16:19
@Shiva sorry, just that point is argued on SO almost every day, and after answering the same question on a daily basis, it gets a little dry after awhile ;) It wasn't intended to be mean, more an expression of flabbergast. — brandonscript, Dec 12 '13 at 16:22
@r3mus Ok. Why would you even be flabbergasted? I never claimed or implied that `JSON` was a regular language. I mean, the expansion of `JSON` should be clear enough to even a non-programmer that 'JavaScript Object Notation` mean a data format, not a language construct. — Shiva, Dec 12 '13 at 16:28
@Shiva fair enough. It's early in the morning for me and I'm cantankerous ;) — brandonscript, Dec 12 '13 at 16:31

falsetru · Accepted Answer · 2013-12-12T16:21:03.740

Using positive lookaround assertions:

string str = "{ name: \"Phai dấu cuộc tình\", mp3: \"audio\\16\\Phai dau cuoc tinh.mp3\"},{ name: \"Caravan of life\", mp3: \"audio\\4\\Caravan of life.mp3\"},{ name: \"I'm Forbidden\", mp3: \"audio\\11\\I'm Forbidden.mp3\"},{ name: \"Cause i love you\", mp3: \"audio\\6\\Cause i love you.mp3\"},{ name: \"Chỉ là giấc mơ\", mp3: \"audio\\8\\Chi la giac mo.mp3\"},{ name: \"Lột xác\", mp3: \"audio\\12\\Lot xac.mp3\"}";

foreach (var match in Regex.Matches(str, @"(?<=\\)\d+(?=\\)"))
    Console.WriteLine(match);

Alternative: capturing group

foreach (Match match in Regex.Matches(str, @"\\(\d+)\\"))
    Console.WriteLine(match.Groups[1]);

ideone

split number from a string in c#

1 Answers1