如何循环使用不同类型的类数组并在swift中打印它们的属性？

Question

I am learning to work with classes and now I need to loop through array of classes with different types and print their properties.

It was not a problem, when there was only one super class and few subclasses, but problem occurred, when I added another superclass and it's subclasses. xCode told me to cast my array as [Any] and I lost my ability to rich class properties.

let human = People(name: "John Dou", height: 180, weight: 80, gender: "male") //every class inherits from class People this way
var peopleArray = [human, cook, manager, fighter] // this is an array of classes with type People

for person in peopleArray {
print(person.name, person.height, person.weight, person.gender)

person.say()
}

This for in loop works fine.

Then I created few classes, which inherits from class Marsian:

let marsian = Marsian(numberOfLegs: 1, planetOfBirth: "Mars")

Then I tried to put instances of every class in an array:

let unitedRaceArray = [marsian, snikersian, twixian, austronaut, fighter, manager, cook, human]

But it shawed me an error: "Heterogeneous collection literal could only be inferred to '[Any]'; add explicit type annotation if this is intentional"

Of course, with type [Any], "for in" loop doesn't work.

Answer 1

Write

let unitedRaceArray: [People]

and you should be fine. If you want to access Martian's write

if let martian = person as? Martian {
}