A little truncate function extension for the default String type (Swift 3 Ready)

string-truncate.swift

extension String {
    /**
     Truncates the string to the specified length number of characters and appends an optional trailing string if longer.
     
     - Parameter length: A `String`.
     - Parameter trailing: A `String` that will be appended after the truncation.
    
     - Returns: A `String` object. 
     */
    func truncate(length: Int, trailing: String = "…") -> String {
        if self.characters.count > length {
            return String(self.characters.prefix(length)) + trailing
        } else {
            return self
        }
    }
}

// Swift 3.0 Example
let str = "This is a long string".truncate(10, trailing: "...") // "This is a ..."

Swift 3 Ready with Proper Documentation Added.

Nice solution, thanks!

Good job! Thanks for sharing!

Swift 4 version: https://gist.github.com/budidino/8585eecd55fd4284afaaef762450f98e

Thanks for sharing!!!

Awesome! Thanks :-)

        return String(self.characters.prefix(length)) + trailing

should be
return String(self.utf8.prefix(length)) + trailing

thanks