将值从数组添加到 int 的问题

Question

嗨，我在 swift

中创建了数组

var age = [
    "Anna": 25,
    "Billy": 32,
]

而且我想将 Anna 的年龄添加到 int

var year = age['Anna']+1965

但我收到错误

Value of optional type 'Int?' must be unwrapped to a value of type 'Int'

所以我尝试做类似

的事情

Int(age['Anna'])

如您所料，它不起作用

Answer 1

因为age['Anna']是Optional<Int>。这不是 Int

你必须展开：

var year = (age['Anna'] ?? 0) + 1965 或

guard let age = age['Anna'] else {
return
}
var year age + 1965

Answer 2

您是否尝试打开 Optional 的包装？

if let ageAnna = age["Anna"] {
    let year = ageAnna + 1965
    print(year)
}