Check if `Any` value is object

Question

I was surprised to find that this condition is always true:

let foo: Any = 4
if let object = foo as? AnyObject {
    print(\"It\'s an object.\")
    //do som         


        

Answer 1

Perhaps you want to look at Mirror which allows a degree of introspection. Documentation is here

import Foundation

func prettyPrint(_ any: Any) -> String {
    let m = Mirror(reflecting: any)
    switch m.displayStyle {
    case .some(.class): // ****
        return "Class"
    case .some(.collection):
        return "Collection, \(m.children.count) elements"
    case .some(.tuple):
        return "Tuple, \(m.children.count) elements"
    case .some(.dictionary):
        return "Dictionary, \(m.children.count) elements"
    case .some(.set):
        return "Set, \(m.children.count) elements"
    case .some(.optional):
        return "Optional"
    case .some(.enum):
        return "Enum"
    case .some(.struct):
        return "Struct"
    default:
        return "\(String(describing: m.displayStyle))"
    }
}
class A {}

prettyPrint([1, 2, 3]) // "Collection, 3 elements"
prettyPrint(Set()) // "Set, 0 elements"
prettyPrint([1: 2, 3: 4]) // "Dictionary, 2 elements"
prettyPrint((1, 2, 3)) // "Tuple, 3 elements"
prettyPrint(3) // "nil"
prettyPrint("3") // "nil"
prettyPrint(NSObject()) // "Class"
prettyPrint(NSArray(array:[1, 2, 3])) // "Collection, 3 elements"
prettyPrint(A()) // "Class"

// prettyPrint(nil) // Compile time error "Nil is not compatible with Any