Swift 3 Tutorials :- String and Character Variables

 These are formatted so you can copy the code straight into your Swift Playground files.

/// variable of Character type that is just a single character

var singleLetter:Character = "F"

// string type variable, contains as many letters, numbers, etc as you want

var mishMash:String = "sdf2325&803!!~"

// create an array of Characters

var letters:[Character] = ["C", "A","R", "T","O", "O","N", "S","M", "A","R", "T", ".", "c", "o", "m"]

//convert the letters array into a string variable named website

var website:String = String (letters)

// lets play around....

print (letters.count)  // prints the number of objects in the array

print (website.characters.count ) //prints the same value

//test to see if converting it all to lower case equals "cartoonsmart.com"

if ( website.lowercased() == "cartoonsmart.com") {

    print (website.lowercased())

    //note in Swift 3 this is lowercased(). In Swift 2 it was lowercaseString

}

let capFirstLetters = website.capitalized  //capFirstLetters would be "Cartoonsmart.Com"

//note in Swift 3 this is .capitalized. In Swift 2 it was capitalizedString

//test to see if website contains a range of ".com"

if ( website.range(of: ".com") != nil) {

    //note in Swift 2, this would have been .rangeOfString(".com")

    print ("it has the dot com")

}

if ( website.lowercased().hasPrefix("car")) {

    //do something if the string begins with "car"

    print ("true")

}

if ( website.hasSuffix(".net")) {

    // do something if its .net

    print ("true")

} else {

    //its not .net

    print ("not true")

}

refrence- http://swift3tutorials.com/