Character Surround Code Exercise

Playground.swift

// Tweet: https://twitter.com/christianselig/status/1471197660111593473?s=12

let input = "|||||"

// option 1 - works but is not generic to be reused with other characters
input.replacingOccurrences(of: "|", with: "n|") + "n"

// option 2 - this function is more flexible and allows input to have any characters
func surround(input: String, spacer: String) -> String {
    input.isEmpty ? input : input.map { "\(spacer)\($0)" }.joined() + spacer
}

surround(input: input, spacer: "n")

// an empty string is handled with a ternary operator with a single line
surround(input: "", spacer: "n")