Extract string within bracket in Swift using regex

Question

I have a scenario where i want to extract the string within bracket after each selected string

PS=AV_2
PS=AV_2(AA)
PS=AV_2(AA),PS=AV_20(BB,ZZ)
PS=AV_2,PS=AV_20
PS=AV_2(ZZ),PS=AV_20

eg. input will be PS=AV_2(AA),PS=AV_20(BB,ZZ) and selectedQues = AV_20 or AV_2 In above only constant part is "PS=" all other string can be anything and any format.

The function should return the string in bracket.

func getStringList(input: String, selectedQues: String ) -> [String] {

       // let pattern = "/\\((.*)\\)/"  //1. "/\(([^)]+)\)/"   //2. "/\\(([^)]+)\\)/)"  //3. "([\\w]+(?:,[\\w]+))" some tried regular expression
        let pattern = "/\(selectedQues)\\(([^)]+)\\)/g"
        let nsString = input as NSString
        let regExp = try! NSRegularExpression(pattern: pattern, options: .CaseInsensitive)
        let results = regExp.matchesInString(input, options: [], range:NSMakeRange(0, nsString.length))

        return results.map { nsString.substringWithRange($0.range)}
}

I am unable to resolve a regular expression for the same. I would be really grateful if someone can help or point to some help.

You cannot use regex delimiters in Swift regex. Try `let pattern = "\(selectedQues)\\(([^)]+)\\)"` — Wiktor Stribiżew, Feb 02 '16 at 11:36
BTW, you can use the code to access Group 1 text from [this answer](http://stackoverflow.com/a/31368973/3832970). — Wiktor Stribiżew, Feb 02 '16 at 11:48
Did you check your code with the one in my previous answer? In your code, you are not accessing the captured text, you only try to access the matches. — Wiktor Stribiżew, Feb 02 '16 at 11:54
For PS=AV_2(AA) it is returning me AV_2(AA) but i expect only AA to be returned by function. Also for PS=AV_2(AA),PS=AV_20(BB,ZZ) the app is crashing — nkp, Feb 02 '16 at 12:44
@wiktor stribizew: Can you tell me regex to get string within the bracket — nkp, Feb 03 '16 at 05:28
Why don't you want to use the capturing group? It is more efficient. What if your selectedques become patterns of uknown width? You wouldn't be able to use a lookbehind. — Wiktor Stribiżew, Feb 03 '16 at 06:52
Ok, try `let pattern = "(?<=\(selectedQues)\\()[^)]+(?=\\))"` — Wiktor Stribiżew, Feb 03 '16 at 07:36
Let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/102440/discussion-between-nkp-and-wiktor-stribizew). — nkp, Feb 03 '16 at 08:24

Extract string within bracket in Swift using regex

0 Answers0