import UIKit

// - Not optioal
var name = ""
var asd = 0.0

// - Optional
var fullName: String?
// var fullName: String? = nil

print(fullName)

fullName = "Denis Baydan"
print(fullName)

fullName = "Deasdasd"
print(fullName)

fullName = nil
print(fullName)

// ---
var age: Int? = 23

print(age)

age = nil
print(age)

age = 119

// ---
var age2 = age ?? 0
print(age2)