String+Extensions.swift

extension String {
    func localized(_ args: CVarArg...) -> String {
        return String(format: NSLocalizedString(self, comment: ""), arguments: args)
    }
}

let format = NSLocalizedString("Hello %@", comment: "")
print(String(format: format, "World"))

print("Hello %@ %@".localized("Worlds", "Fair"))


let format2 = "Hello %@ %@"
print(format2.localized("Worlds", "Fair"))