78051
Question:
I have an AnyObject type that can be String, Int or Bool type. I need to distinguish them.
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
Answer1:
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 cannot be implicitly downcast to any type in Swift. For such case you can use Generics instead.
Generic code enables you to write flexible, reusable functions and types that can work with any type, subject to requirements that you define. <a href="https://developer.apple.com/library/mac/documentation/Swift/Conceptual/Swift_Programming_Language/Generics.html" rel="nofollow">Read more</a>.
</blockquote> Answer2:The way worked with me is by using the <strong>Mirror</strong> struct.
let value: Any? = 867
let stringMirror = Mirror(reflecting: value!)
let type = stringMirror.subjectType
print(stringMirror.subjectType)
if type == Bool.self {
print("type is Bool")
} else if type == String.self {
print("type is string")
} else if type == Int.self {
print("type is Int")
}
use <strong>Any</strong> here since <em>Int, String, Bool</em> are structs. if you just try to distinguish between classes using <strong>is</strong> should work.
if value is NSString {
print("type is NSString")
}
