to Call subclasses that have same variable and value

Question

so I have Animal superclass and three subclass : lion dog and elephant.

enum Gender {
    case male
    case female
}

class Animal {
    var species: String
    var gender: Gender

    init (species: String, gender: Gender) {
        self.species = species
        self.gender = gender
    }
}

// Lion Class    
class Lion: Animal {
    var age: Int = 10

    init () {
        super.init(species: "Lion", gender: Gender.male)
    }
}

// Elephant Class
class Elephant: Animal {    
    var age: Int = 8

    init () {
        super.init(species: "Elephant", gender: Gender.female)
    }
}

//Dog Class
class Dog: Animal {
    var age: Int = 6

    init () {
        super.init(species: "Dog", gender: Gender.female)
    }
}

They all have gender variable which is inherited from superclass Animal. Now I want to have a computed property: maleAnimal of type [Animal] which contains all male animal, what is the best way to do it ?

class Zoo {
    var animals: [Animal] = [Lion(), Elephant(), Dog()]

    var maleAnimals: [Animal] {
        for animalClasses in animals {
            if animalClasses.gender == Gender.male {
               return self.maleAnimals.append(animalClasses)
            }
        }
    }
}

I have tried some thing like the example beneath but it apparently does not work.

Any hints are appreciated!

Answer 1

You can use the filter method on arrays.

var maleAnimals : [Animal] {
    return animals.filter { $0.gender == .male }
}