“不推荐使用‘init’

问题描述：

在 Swift3 中，我之前使用以下方法将 Bool 转换为 Int

In Swift3, I previously converted a Bool to an Int using the following method

let _ = Int(NSNumber(value: false))

转换为 Swift4 后，我收到'init' is deprecated"警告.还应该怎么做?

After converting to Swift4, I'm getting a "'init' is deprecated" warning. How else should this be done?

答

使用 Swift 4.2 和 Swift 5，您可以选择以下 5 种解决方案之一来解决您的问题.

With Swift 4.2 and Swift 5, you can choose one of the 5 following solutions in order to solve your problem.

import Foundation

let integer = NSNumber(value: false).intValue
print(integer) // prints 0

#2.使用类型转换

import Foundation

let integer = NSNumber(value: false) as? Int
print(String(describing: integer)) // prints Optional(0)

#3.使用 `Int` 的 `init(exactly:)` 初始化器

import Foundation

let integer = Int(exactly: NSNumber(value: false))
print(String(describing: integer)) // prints Optional(0)

作为前面代码的替代，您可以使用下面更简洁的代码.

As an alternative to the previous code, you can use the more concise code below.

import Foundation

let integer = Int(exactly: false)
print(String(describing: integer)) // prints Optional(0)

import Foundation

let integer = Int(truncating: false)
print(integer) // prints 0

注意以下示例代码不需要导入 Foundation.

Note that the following sample codes do not require to import Foundation.

用法 #1(if 语句):

let integer: Int
let bool = false

if bool {
    integer = 1
} else {
    integer = 0
}
print(integer) // prints 0

用法#2(三元运算符):

let integer = false ? 1 : 0
print(integer) // prints 0