Answer by Maksim Kniazev for How to remove special characters from string in Swift 2?

SWIFT 4:

func removeSpecialCharsFromString(text: String) -> String {
    let okayChars = Set("abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLKMNOPQRSTUVWXYZ1234567890+-=().!_")
    return text.filter {okayChars.contains($0) }
}

More cleaner way:

extension String {

    var stripped: String {
        let okayChars = Set("abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLKMNOPQRSTUVWXYZ1234567890+-=().!_")
        return self.filter {okayChars.contains($0) }
    }
}

Use this extension like:

let myCleanString = "some.Text@#$".stripped

Output: "some.Text"