Use filter() on a string in Swift 2 -

i'm not sure if api in swift 2 changed, can't filter work on string in swift 2. following should change "abc123$$$ ff" "abcff".

// removes special characters , whitespaces func compressstring(astring: string) -> string{     let charset = nscharacterset.lettercharacterset()  // following don't work: //    return astring.filter{charset.contains($0)} //    return string(filter(astring).{charset.contains($0)}) } 

if want use filter, need run on characters view:

// removes special characters , whitespaces func compressstring(astring: string) -> string{     let charset: [character] = ["$", " ", "1", "2", "3"]      // following don't work:     return string(astring.characters.filter { !charset.contains($0) }) }  let before = "abc123$$$ ff"   let after = compressstring(before) // "abcff"