var tempstr ="? ? ? !!Swift"
tempstr.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceCharacterSet())
//"!!swift"
tempstr.stringByTrimmingCharactersInSet(NSCharacterSet(charactersInString:"!"))
//"swift"
var tempstr ="? ? ? !!Swift"
tempstr.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceCharacterSet())
//"!!swift"
tempstr.stringByTrimmingCharactersInSet(NSCharacterSet(charactersInString:"!"))
//"swift"