Related
I'm used to do this in JavaScript:
var domains = "abcde".substring(0, "abcde".indexOf("cd")) // Returns "ab"
Swift doesn't have this function, how to do something similar?
edit/update:
Xcode 11.4 • Swift 5.2 or later
import Foundation
extension StringProtocol {
func index<S: StringProtocol>(of string: S, options: String.CompareOptions = []) -> Index? {
range(of: string, options: options)?.lowerBound
}
func endIndex<S: StringProtocol>(of string: S, options: String.CompareOptions = []) -> Index? {
range(of: string, options: options)?.upperBound
}
func indices<S: StringProtocol>(of string: S, options: String.CompareOptions = []) -> [Index] {
ranges(of: string, options: options).map(\.lowerBound)
}
func ranges<S: StringProtocol>(of string: S, options: String.CompareOptions = []) -> [Range<Index>] {
var result: [Range<Index>] = []
var startIndex = self.startIndex
while startIndex < endIndex,
let range = self[startIndex...]
.range(of: string, options: options) {
result.append(range)
startIndex = range.lowerBound < range.upperBound ? range.upperBound :
index(range.lowerBound, offsetBy: 1, limitedBy: endIndex) ?? endIndex
}
return result
}
}
usage:
let str = "abcde"
if let index = str.index(of: "cd") {
let substring = str[..<index] // ab
let string = String(substring)
print(string) // "ab\n"
}
let str = "Hello, playground, playground, playground"
str.index(of: "play") // 7
str.endIndex(of: "play") // 11
str.indices(of: "play") // [7, 19, 31]
str.ranges(of: "play") // [{lowerBound 7, upperBound 11}, {lowerBound 19, upperBound 23}, {lowerBound 31, upperBound 35}]
case insensitive sample
let query = "Play"
let ranges = str.ranges(of: query, options: .caseInsensitive)
let matches = ranges.map { str[$0] } //
print(matches) // ["play", "play", "play"]
regular expression sample
let query = "play"
let escapedQuery = NSRegularExpression.escapedPattern(for: query)
let pattern = "\\b\(escapedQuery)\\w+" // matches any word that starts with "play" prefix
let ranges = str.ranges(of: pattern, options: .regularExpression)
let matches = ranges.map { str[$0] }
print(matches) // ["playground", "playground", "playground"]
Using String[Range<String.Index>] subscript you can get the sub string. You need starting index and last index to create the range and you can do it as below
let str = "abcde"
if let range = str.range(of: "cd") {
let substring = str[..<range.lowerBound] // or str[str.startIndex..<range.lowerBound]
print(substring) // Prints ab
}
else {
print("String not present")
}
If you don't define the start index this operator ..< , it take the starting index. You can also use str[str.startIndex..<range.lowerBound] instead of str[..<range.lowerBound]
Swift 5
Find index of substring
let str = "abcdecd"
if let range: Range<String.Index> = str.range(of: "cd") {
let index: Int = str.distance(from: str.startIndex, to: range.lowerBound)
print("index: ", index) //index: 2
}
else {
print("substring not found")
}
Find index of Character
let str = "abcdecd"
if let firstIndex = str.firstIndex(of: "c") {
let index = str.distance(from: str.startIndex, to: firstIndex)
print("index: ", index) //index: 2
}
else {
print("symbol not found")
}
In Swift 4 :
Getting Index of a character in a string :
let str = "abcdefghabcd"
if let index = str.index(of: "b") {
print(index) // Index(_compoundOffset: 4, _cache: Swift.String.Index._Cache.character(1))
}
Creating SubString (prefix and suffix) from String using Swift 4:
let str : String = "ilike"
for i in 0...str.count {
let index = str.index(str.startIndex, offsetBy: i) // String.Index
let prefix = str[..<index] // String.SubSequence
let suffix = str[index...] // String.SubSequence
print("prefix \(prefix), suffix : \(suffix)")
}
Output
prefix , suffix : ilike
prefix i, suffix : like
prefix il, suffix : ike
prefix ili, suffix : ke
prefix ilik, suffix : e
prefix ilike, suffix :
If you want to generate a substring between 2 indices , use :
let substring1 = string[startIndex...endIndex] // including endIndex
let subString2 = string[startIndex..<endIndex] // excluding endIndex
Doing this in Swift is possible but it takes more lines, here is a function indexOf() doing what is expected:
func indexOf(source: String, substring: String) -> Int? {
let maxIndex = source.characters.count - substring.characters.count
for index in 0...maxIndex {
let rangeSubstring = source.startIndex.advancedBy(index)..<source.startIndex.advancedBy(index + substring.characters.count)
if source.substringWithRange(rangeSubstring) == substring {
return index
}
}
return nil
}
var str = "abcde"
if let indexOfCD = indexOf(str, substring: "cd") {
let distance = str.startIndex.advancedBy(indexOfCD)
print(str.substringToIndex(distance)) // Returns "ab"
}
This function is not optimized but it does the job for short strings.
There are three closely connected issues here:
All the substring-finding methods are over in the Cocoa NSString world (Foundation)
Foundation NSRange has a mismatch with Swift Range; the former uses start and length, the latter uses endpoints
In general, Swift characters are indexed using String.Index, not Int, but Foundation characters are indexed using Int, and there is no simple direct translation between them (because Foundation and Swift have different ideas of what constitutes a character)
Given all that, let's think about how to write:
func substring(of s: String, from:Int, toSubstring s2 : String) -> Substring? {
// ?
}
The substring s2 must be sought in s using a String Foundation method. The resulting range comes back to us, not as an NSRange (even though this is a Foundation method), but as a Range of String.Index (wrapped in an Optional, in case we didn't find the substring at all). However, the other number, from, is an Int. Thus we cannot form any kind of range involving them both.
But we don't have to! All we have to do is slice off the end of our original string using a method that takes a String.Index, and slice off the start of our original string using a method that takes an Int. Fortunately, such methods exist! Like this:
func substring(of s: String, from:Int, toSubstring s2 : String) -> Substring? {
guard let r = s.range(of:s2) else {return nil}
var s = s.prefix(upTo:r.lowerBound)
s = s.dropFirst(from)
return s
}
Or, if you prefer to be able to apply this method directly to a string, like this...
let output = "abcde".substring(from:0, toSubstring:"cd")
...then make it an extension on String:
extension String {
func substring(from:Int, toSubstring s2 : String) -> Substring? {
guard let r = self.range(of:s2) else {return nil}
var s = self.prefix(upTo:r.lowerBound)
s = s.dropFirst(from)
return s
}
}
Swift 5
let alphabet = "abcdefghijklmnopqrstuvwxyz"
var index: Int = 0
if let range: Range<String.Index> = alphabet.range(of: "c") {
index = alphabet.distance(from: alphabet.startIndex, to: range.lowerBound)
print("index: ", index) //index: 2
}
Swift 5
extension String {
enum SearchDirection {
case first, last
}
func characterIndex(of character: Character, direction: String.SearchDirection) -> Int? {
let fn = direction == .first ? firstIndex : lastIndex
if let stringIndex: String.Index = fn(character) {
let index: Int = distance(from: startIndex, to: stringIndex)
return index
} else {
return nil
}
}
}
tests:
func testFirstIndex() {
let res = ".".characterIndex(of: ".", direction: .first)
XCTAssert(res == 0)
}
func testFirstIndex1() {
let res = "12345678900.".characterIndex(of: "0", direction: .first)
XCTAssert(res == 9)
}
func testFirstIndex2() {
let res = ".".characterIndex(of: ".", direction: .last)
XCTAssert(res == 0)
}
func testFirstIndex3() {
let res = "12345678900.".characterIndex(of: "0", direction: .last)
XCTAssert(res == 10)
}
In the Swift version 3, String doesn't have functions like -
str.index(of: String)
If the index is required for a substring, one of the ways to is to get the range. We have the following functions in the string which returns range -
str.range(of: <String>)
str.rangeOfCharacter(from: <CharacterSet>)
str.range(of: <String>, options: <String.CompareOptions>, range: <Range<String.Index>?>, locale: <Locale?>)
For example to find the indexes of first occurrence of play in str
var str = "play play play"
var range = str.range(of: "play")
range?.lowerBound //Result : 0
range?.upperBound //Result : 4
Note : range is an optional. If it is not able to find the String it will make it nil. For example
var str = "play play play"
var range = str.range(of: "zoo") //Result : nil
range?.lowerBound //Result : nil
range?.upperBound //Result : nil
Leo Dabus's answer is great. Here is my answer based on his answer using compactMap to avoid Index out of range error.
Swift 5.1
extension StringProtocol {
func ranges(of targetString: Self, options: String.CompareOptions = [], locale: Locale? = nil) -> [Range<String.Index>] {
let result: [Range<String.Index>] = self.indices.compactMap { startIndex in
let targetStringEndIndex = index(startIndex, offsetBy: targetString.count, limitedBy: endIndex) ?? endIndex
return range(of: targetString, options: options, range: startIndex..<targetStringEndIndex, locale: locale)
}
return result
}
}
// Usage
let str = "Hello, playground, playground, playground"
let ranges = str.ranges(of: "play")
ranges.forEach {
print("[\($0.lowerBound.utf16Offset(in: str)), \($0.upperBound.utf16Offset(in: str))]")
}
// result - [7, 11], [19, 23], [31, 35]
Have you considered using NSRange?
if let range = mainString.range(of: mySubString) {
//...
}
I got HTML string from API like this:
let a: String = "https://www.google.com.tw "
let b: String = "#Tim Hello Tim"
let c: String = "#Tim https://www.google.com.tw "
let splitedArray1: [String] = a.componentsSeparatedByString("?????") //splited string which is the best
let splitedArray2: [String] = b.componentsSeparatedByString("?????") //splited string which is the best
let splitedArray3: [String] = c.componentsSeparatedByString("?????") //splited string which is the best
I want to separate link from them and get the data like following
print(splitedArray1) //["https://www.google.com.tw","https://www.google.com.tw"]
print(splitedArray2) //["myAppName://app/user/aa3b77411825b88b318d77gg","#Tim ","Hello Tim"]
print(splitedArray3) //["myAppName://app/user/aa3b77411825b88b318d77gg","#Tim ","https://www.google.com.tw","https://www.google.com.tw "]
Possible solution: Use NSAttributedString then enumerate on the NSLinkAttributeName, if there isn't, it means there were no link tag, so you just keep the "string", else, you add the link, then the string.
Quickly written in Playground:
let a: String = "https://www.google.com.tw "
let b: String = "#Tim Hello Tim"
let c: String = "#Tim https://www.google.com.tw "
let values:[String] = [a, b, c]
for aHTMLString in values
{
let attributedString = try! NSAttributedString.init(data: aHTMLString.data(using: .utf8)!,
options: [.documentType: NSAttributedString.DocumentType.html],
documentAttributes: nil)
var retValues = [String]()
attributedString.enumerateAttribute(.link,
in: NSRange(location: 0, length: attributedString.string.count),
options: [],
using: { (attribute, range, pointerStop) in
if let attribute = attribute as? URL
{
retValues.append(attribute.absoluteString)
}
let subString = (attributedString.string as NSString).substring(with: range)
retValues.append(subString)
})
print("*** retValues: \(retValues)")
}
let targetResult1 = ["https://www.google.com.tw","https://www.google.com.tw"]
let targetResult2 = ["myAppName://app/user/aa3b77411825b88b318d77gg","#Tim ","Hello Tim"]
let targetResult3 = ["myAppName://app/user/aa3b77411825b88b318d77gg","#Tim ","https://www.google.com.tw","https://www.google.com.tw "]
print("targetResult1: \(targetResult1)")
print("targetResult2: \(targetResult2)")
print("targetResult3: \(targetResult3)")
Output:
*** retValues: ["https://www.google.com.tw/", "https://www.google.com.tw "]
*** retValues: ["myappname://app/user/aa3b77411825b88b318d77gg", "#Tim ", "Hello Tim"]
*** retValues: ["myappname://app/user/aa3b77411825b88b318d77gg", "#Tim ", "https://www.google.com.tw/", "https://www.google.com.tw "]
targetResult1: ["https://www.google.com.tw", "https://www.google.com.tw"]
targetResult2: ["myAppName://app/user/aa3b77411825b88b318d77gg", "#Tim ", "Hello Tim"]
targetResult3: ["myAppName://app/user/aa3b77411825b88b318d77gg", "#Tim ", "https://www.google.com.tw", "https://www.google.com.tw "]
There are small differences, I copied your "target" (splitArray), and it's missing a space in the last one, and my code tend to add a final "/" on links.
I've created this extension to get url.
extension String {
func getUrl() -> String? {
let rss = self.split { (char) -> Bool in
return char == ">"
}
if let final = rss.last?.split(separator: "<"), let first = final.first {
return String(first)
}
return nil
}
var hrefUrl: String {
let matchString = "=\""
let arrComponents = self.components(separatedBy: matchString)
if let first = arrComponents.last, let str = first.split(separator: "\"").first {
return String(str)
}
return ""
}
}
Usage:
let a: String = "https://www.google.com.tw "
a.getUrl() //output: https://www.google.com.tw
//or
a.hrefUrl //output: https://www.google.com.tw
Simple solution without libraries - just use String.replaceOccurences(of:... to replace odd strings like a href, a into split parameter (like "|") and then use componentsSeparatedByString("|") to get your components.
Use the regular expression for extracting the URL. Below I have written the code snippet.
let text = "<a href=\"https://www.google.com\">"
let regex = try! NSRegularExpression(pattern: "<a[^>]+href=\"(.*?)\"[^>]*>")
let range = NSMakeRange(0, text.characters.count)
let matches = regex.matches(in: text, range: range)
for match in matches {
let strURL = (text as NSString).substring(with: match.rangeAt(1))
print(strURL)
}
Relatively new to Swift programming.
I get an dictionary from which I need to get the user name (first and last name) and display it in table view cell along with other data.
On iPhone 5 and below as the screen width is only 320, the requirement is to just display the first name and first character of the last name.
E.g: "Howard Mark" to "Howard M"
I am sure that there is an elegant way to extract the required string.
struct ScreenSize
{
static let SCREEN_WIDTH = UIScreen.main.bounds.size.width
static let SCREEN_HEIGHT = UIScreen.main.bounds.size.height
static let SCREEN_MAX_LENGTH = max(ScreenSize.SCREEN_WIDTH, ScreenSize.SCREEN_HEIGHT)
static let SCREEN_MIN_LENGTH = min(ScreenSize.SCREEN_WIDTH, ScreenSize.SCREEN_HEIGHT)
}
struct DeviceType
{
static let IS_IPHONE_5_OR_LESS = (UIDevice.current.userInterfaceIdiom == .phone && ScreenSize.SCREEN_MAX_LENGTH <= 568.0)
}
func functionCall (referralData:[String: Any?])
{
var myMutableString = NSMutableAttributedString()
if var nameString = referralData[KEY_FULL_NAME]
{
if DeviceType.IS_IPHONE_5_OR_LESS
{
var a = nameString as? NSString
var arr = a?.components(separatedBy: " ")
let newStr = arr?[0] as? String
nameString = newStr
if((arr?.count)! > 1)
{
if let secondString = arr?[1]
{
let newStr2 = newStr as? NSString
let secondChar = newStr2?.character(at: 0)
let stringchar:String! = String(secondChar!)
nameString = "\(newStr!) \(stringchar)"
}
}
print("iPhone 5 or less")
}
else
{
print("Greater than iPhone 5")
}
}
}
I don't think anyone should be thinking in Swift 3 any more. Here's a Swift 4 example:
var name = "Veeblefetzer Rumplestiltskin"
if let r = name.range(of: " ", options: .backwards, range: name.startIndex..<name.endIndex) {
name = String(name[name.startIndex..<name.index(r.upperBound, offsetBy: 1)])
}
name // "Veeblefetzer R"
maybe like this?
let fullName = "Dominik Pich"
var parts = fullName.components(separatedBy: " ")
if parts.count > 0,
let lastNameInitial = parts.last?.prefix(1) {
parts[parts.count-1] = String(lastNameInitial)
}
let truncatedName = parts.joined(separator: " ")
//use
print("fullName: \(fullName)")
print("truncatedName: \(truncatedName)")
I'd wrap it in a nice String extension - e.g. a computed property truncateLast
The most helpful answer I've found when using Swift's built in substring command is here: https://stackoverflow.com/a/39677331/5495979
Although, using the substring command still requires you to first obtain a range or an index, so it still requires a couple commands to implement.
So Using my preferred method from the SO answer referenced above I would just grab the index of the first character and use the substring command and cast it to a string:
let index = secondString.index(secondString.startIndex, offsetBy: 0)
let stringChar = String(secondString.substring(to: index))
I also wanted to let you know that there appears to be a logic error in your code when obtaining the first letter of the last name. You unwrap what should be the last name in your string components array with if let secondString = arr?[1] but then don't assign the unwrapped string stored in secondString to newStr2 before parsing newStr2 for the first character in the string. As it appears now when you parse the first character of the string with let secondChar = newStr2?.character(at: 0) you will actually be parsing the first character from the first name (since when assigning newStr2 with let newStr2 = newStr as? NSString you are actually assigning the fist entry from the array of name strings since newStr is only assinged with let newStr = arr?[0] as? String)
My code snippet is:
unwanted = " £€₹jetztabfromnow"
let favouritesPriceLabel = priceDropsCollectionView.cells.element(boundBy: UInt(index)).staticTexts[IPCUIAHighlightsPriceDropsCollectionViewCellPriceLabel].label
let favouritesPriceLabelTrimmed = favouritesPriceLabel.components(separatedBy: "jetzt").flatMap { String($0.trimmingCharacters(in: .whitespaces)) }.last
favouritesHighlightsDictionary[favouritesTitleLabel] = favouritesPriceLabelTrimmed
My problem is, this didn't work:
let favouritesPriceLabelTrimmed = favouritesPriceLabel.components(separatedBy: unwanted).flatMap { String($0.trimmingCharacters(in: .whitespaces)) }.last
I have a price like "from 3,95 €" - I want to cut all currencies "£€₹" and words like "from" or "ab"
Do you have a solution for me, what I can use here?
Rather than mess around with trying to replace or remove the right characters or using regular expressions, I'd go with Foundation's built-in linguistic tagging support. It will do a lexical analysis of the string and return tokens of various types. Use it on this kind of string and it should reliably find any numbers in the string.
Something like:
var str = "from 3,95 €"
let range = Range(uncheckedBounds: (lower: str.startIndex, upper: str.endIndex))
var tokenRanges = [Range<String.Index>]()
let scheme = NSLinguisticTagSchemeLexicalClass
let option = NSLinguisticTagger.Options()
let tags = str.linguisticTags(in: range, scheme: scheme, options: option, orthography: nil, tokenRanges: &tokenRanges)
let tokens = tokenRanges.map { str.substring(with:$0) }
if let numberTagIndex = tags.index(where: { $0 == "Number" }) {
let number = tokens[numberTagIndex]
print("Found number: \(number)")
}
In this example the code prints "3,95". If you change str to "from £28.50", it prints "28.50".
One way is to place the unwanted strings into an array, and use String's replacingOccurrences(of:with:) method.
let stringToScan = "£28.50"
let toBeRemoved = ["£", "€", "₹", "ab", "from"]
var result = stringToScan
toBeRemoved.forEach { result = result.replacingOccurrences(of: $0, with: "") }
print(result)
...yields "28.50".
If you just want to extract the numeric value use regular expression, it considers comma or dot decimal separators.
let string = "from 3,95 €"
let pattern = "\\d+[.,]\\d+"
do {
let regex = try NSRegularExpression(pattern: pattern, options: [])
if let match = regex.firstMatch(in: string, range: NSRange(location: 0, length: string.utf16.count)) {
let range = match.range
let start = string.index(string.startIndex, offsetBy: range.location)
let end = string.index(start, offsetBy: range.length)
print(string.substring(with: start..<end)) // 3,95
} else {
print("Not found")
}
} catch {
print("Regex Error:", error)
}
I asked if you had a fixed locale for this string, because then you can use the locale to determine what the decimal separator is: For example, try this in a storyboard.
let string = "some initial text 3,95 €" // define the string to scan
// Add a convenience extension to Scanner so you don't have to deal with pointers directly.
extension Scanner {
func scanDouble() -> Double? {
var value = Double(0)
guard scanDouble(&value) else { return nil }
return value
}
// Convenience method to advance the location of the scanner up to the first digit. Returning the scanner itself or nil, which allows for optional chaining
func scanUpToNumber() -> Scanner? {
var value: NSString?
guard scanUpToCharacters(from: CharacterSet.decimalDigits, into: &value) else { return nil }
return self
}
}
let scanner = Scanner(string: string)
scanner.locale = Locale(identifier: "fr_FR")
let double = scanner.scanUpToNumber()?.scanDouble() // -> double = 3.95 (note the type is Double?)
Scanners are a lot easier to use than NSRegularExpressions in these cases.
You can filter by special character by removing alphanumerics.
extension String {
func removeCharacters(from forbiddenChars: CharacterSet) -> String {
let passed = self.unicodeScalars.filter { !forbiddenChars.contains($0) }
return String(String.UnicodeScalarView(passed))
}
}
let str = "£€₹jetztabfromnow12"
let t1 = str.removeCharacters(from: CharacterSet.alphanumerics)
print(t1) // will print: £€₹
let t2 = str.removeCharacters(from: CharacterSet.decimalDigits.inverted)
print(t2) // will print: 12
Updated 1:
var str = "£3,95SS"
str = str.replacingOccurrences(of: ",", with: "")
let digit = str.removeCharacters(from: CharacterSet.decimalDigits.inverted)
print(digit) // will print: 395
let currency = str.removeCharacters(from: CharacterSet.alphanumerics)
print(currency) // will print: £
let amount = currency + digit
print(amount) // will print: £3,95
Update 2:
let string = "£3,95SS"
let pattern = "-?\\d+(,\\d+)*?\\.?\\d+?"
do {
let regex = try NSRegularExpression(pattern: pattern, options: [])
if let match = regex.firstMatch(in: string, range: NSRange(location: 0, length: string.utf16.count)) {
let range = match.range
let start = string.index(string.startIndex, offsetBy: range.location)
let end = string.index(start, offsetBy: range.length)
let digit = string.substring(with: start..<end)
print(digit) //3,95
let symbol = string.removeCharacters(from: CharacterSet.symbols.inverted)
print(symbol) // £
print(symbol + digit) //£3,95
} else {
print("Not found")
}
} catch {
print("Regex Error:", error)
}
I am trying to trim a phone number and using the following code but it does not trim whitespace or the '-'. I need to erase all chars except those in the character set given
func trimmedNumber(s : String)->String
{
let characterSet = NSCharacterSet(charactersInString: "+*#0123456789")
let trimmedString = s.stringByTrimmingCharactersInSet(characterSet.invertedSet)
return trimmedString
}
Swift 3/4:
let set = CharacterSet(charactersIn: "+*#0123456789")
let stripped = s.components(separatedBy: set.inverted).joined()
func trimmedNumber(s : String) -> String {
let characterSet = Set("+*#0123456789".characters)
return String(s.characters.lazy.filter(characterSet.contains))
}
Or in Swift 1:
func trimmedNumber(s : String) -> String {
let characterSet = Set("+*#0123456789")
return String(lazy(s).filter { characterSet.contains($0) })
}
Add the method removingCharacters(in:) to Swift's String type. It returns a new string made by removing the characters in a given character set from the String.
For example:
let string = "+1-202-555-0141"
let set = CharacterSet(charactersIn: "+*#0123456789")
let sanitized = string.removingCharacters(in: set.inverted)
// sanitized is equal to "+12025550141"
Helpers.swift
extension String {
public func removingCharacters(in set: CharacterSet) -> String {
let filtered = unicodeScalars.filter { !set.contains($0) }
return String(String.UnicodeScalarView(filtered))
}
}
HelpersTests.swift
import XCTest
class HelpersTests: XCTestCase {
func testRemovingCharacters() {
let inputText1 = ""
let set1 = CharacterSet.decimalDigits.inverted
let sanitized1 = inputText1.removingCharacters(in: set1)
XCTAssertEqual("", sanitized1)
let inputText2 = " tab:\tspace: no-break_space: "
let set2 = CharacterSet.whitespaces
let sanitized2 = inputText2.removingCharacters(in: set2)
XCTAssertEqual("tab:space:no-break_space:", sanitized2)
let inputText3 = " aBc!##12 $%^&*()-_=+[{]}\\|;:'\"3,<.>/?`~ "
let set3 = CharacterSet.alphanumerics.inverted
let sanitized3 = inputText3.removingCharacters(in: set3)
XCTAssertEqual("aBc123", sanitized3)
}
}
See also: Convert Array of UnicodeScalar into String in Swift
works in swift 1&2
let s = "adasdad+3124124+r323*4asdasdbk*($&##"
let characterSet = NSCharacterSet(charactersInString: "+*#0123456789").invertedSet;
let elements = s.componentsSeparatedByCharactersInSet(characterSet)
let filtered = (elements as NSArray).componentsJoinedByString("")
print(filtered);