在Swift中可以区分Bool和Int吗? [英] Is it possible to distinguish Bool and Int in Swift?

问题描述

我有一个AnyObject类型，可以是String，Int或Bool类型.我需要区分它们.

I have an AnyObject type that can be String, Int or Bool type. I need to distinguish them.

此代码试图这样做，但是它认为Bool是Int:

This code tries to do so, but it considers Bool to be Int:

import Cocoa

var value: AnyObject

func checkType(value: AnyObject) -> String {
    if let intvalue: Int = value as? Int {
        return("It is an integer")
    } else if let boolvalue: Bool = value as? Bool {
        return("It is an boolean")
    } else if let stringvalue: String = value as? String {
        return("It is an string")
    }
    return "not found"
}

value = "hello"
checkType(value) // It is an string

value = 1
checkType(value) // It is an integer

value = true
checkType(value) // It is an integer

推荐答案

func checkType<T>(value: T) -> String {
    var statusText = "not found"
    if value is Int {
        statusText = "It is an integer"
    } else if value is Bool {
        statusText = "It is an boolean"
    } else if value is String {
        statusText = "It is an string"
    }
    return statusText
}

AnyObject不能隐式向下转换为Swift中的任何类型.在这种情况下，您可以改用Generics.

AnyObject cannot be implicitly downcast to any type in Swift. For such case you can use Generics instead.

使用通用代码，可以根据您定义的要求编写灵活的，可重用的函数和类型，这些函数和类型可以与任何类型一起使用. 了解更多.

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