class.swift

//class version
class TomatoClass {
    
    var name: String
    var state: Bool // true=active, false=pause
    var start_time: Date
    var finish_time: Date?
    var elapsed_time: TimeInterval?
    
    init(name: String, state: Bool, start_time: Date){
        self.name = name
        self.state = state
        self.start_time = start_time
    }
    
    func toggle() {
        state = !state
    }
    
    func finish() {
        finish_time = Date()
        state = false
        elapsed_time = start_time.distance(to: finish_time ?? Date())
    }
}

print("Class version")
var classTomato = TomatoClass(name: "This is class version of tomato struct", state: true, start_time: Date())
print(classTomato.name)