regex to get string between two % characters - ios

Question

I need to extract string between two "%" characters, multiple occurrences can be present in the query string.
now am using the following regex, can somebody help to get the exact Regax format.
let query = "Hello %test% ho do you do %test1%"
let regex = try! NSRegularExpression(pattern:"%(.*?)%", options: [])
if let results = regex?.matchesInString(query, options: .Anchored, range: NSMakeRange(0,query.characters.count)){
for match in results{
}
}

Answer 1

Your pattern is fine but your code didn't compile. Try this instead:
Swift 4
let query = "Hello %test% how do you do %test1%"
let regex = try! NSRegularExpression(pattern:"%(.*?)%", options: [])
var results = [String]()
regex.enumerateMatches(in: query, options: [], range: NSMakeRange(0, query.utf16.count)) { result, flags, stop in
if let r = result?.range(at: 1), let range = Range(r, in: query) {
results.append(String(query[range]))
}
}
print(results) // ["test", "test1"]
NSString uses UTF-16 encoding so NSMakeRange is called with the number of UTF-16 code units.
Swift 2
let query = "Hello %test% how do you do %test1%"
let regex = try! NSRegularExpression(pattern:"%(.*?)%", options: [])
let tmp = query as NSString
var results = [String]()
regex.enumerateMatchesInString(query, options: [], range: NSMakeRange(0, tmp.length)) { result, flags, stop in
if let range = result?.rangeAtIndex(1) {
results.append(tmp.substringWithRange(range))
}
}
print(results) // ["test", "test1"]
Getting a substring out of Swift's native String type is somewhat of a hassle. That's why I casted query into an NSString

Answer 2

I have written a method for regular express. Your regex is fine. You can test your regexes here . The method is:
func regexInText(regex: String!, text: String!) -> [String] {
do {
let regex = try NSRegularExpression(pattern: regex, options: [])
let nsString = text as NSString
let results = regex.matchesInString(text,
options: [], range: NSMakeRange(0, nsString.length))
return results.map { nsString.substringWithRange($0.range)}
} catch let error as NSError {
print("invalid regex: \(error.localizedDescription)")
return []
}
}
You can call it whereever you want.