Get the last character of a string without using array?

Question

I have a string

let stringPlusString = TextBoxCal.text

I want to get the last character of stringPlusString. I do not want to

Answer 1

Details

• Swift 5.1, Xcode 11.2.1

Solution

extension String {
    func onlyLastCharacters(_ count: Int) -> String { return String(suffix(count)) }
    func onlyLastCharacters(_ count: Int, checkLength: Bool) -> String? {
        if checkLength {
            if self.count >= count { return onlyLastCharacters(count) }
            return nil
        }
        return String(suffix(count))
    }
}

Usage

str.onlyLastCharacters(6)
str.onlyLastCharacters(13, checkLength: true)

Full sample

Do not forget to paste here the solution code

var testNumber = 0
func show(original: String, modified: String?) {
    testNumber += 1
    if let string = modified {
        print("\(testNumber). Original: \"\(original)\", modified: \"\(string)\"")
    } else {
        print("\(testNumber). nil | count: nil")
    }
}

var str = "Hello world!"
show(original: str, modified: str.onlyLastCharacters(6))
show(original: str, modified: str.onlyLastCharacters(12))
show(original: str, modified: str.onlyLastCharacters(13, checkLength: false))
show(original: str, modified: str.onlyLastCharacters(13, checkLength: true))

str = ""
show(original: str, modified: str.onlyLastCharacters(10))
show(original: str, modified: str.onlyLastCharacters(10, checkLength: true))
show(original: str, modified: str.onlyLastCharacters(10, checkLength: false))

Log

1. Original: "Hello world!", modified: "world!"
2. Original: "Hello world!", modified: "Hello world!"
3. Original: "Hello world!", modified: "Hello world!"
4. nil | count: nil
5. Original: "", modified: ""
6. nil | count: nil
7. Original: "", modified: ""