Swift 中 java 的 instanceof 相当于什么

Swift 中的类型判断操作符 `is` 相当于 Java 中的 `instanceof`。这两个操作符都用于判断一个对象是否属于特定类或其子类的实例。它们在编程中都起到了相似的作用，但在语法和一些细节上有所不同。

if someInstance is SomeClass {
    // someInstance 是 SomeClass 类型的实例
}

if (someInstance instanceof SomeClass) {
    // someInstance 是 SomeClass 类型的实例
}

swift
class Animal {
    var name: String
    
    init(name: String) {
        self.name = name
    }
}
class Lion: Animal {
    func roar() {
        print("The lion is roaring!")
    }
}
class Elephant: Animal {
    func trumpet() {
        print("The elephant is trumpeting!")
    }
}
let animals: [Animal] = [Lion(name: "Simba"), Elephant(name: "Dumbo")]
for animal in animals {
    if animal is Lion {
        let lion = animal as! Lion
        lion.roar()
    } else if animal is Elephant {
        let elephant = animal as! Elephant
        elephant.trumpet()
    } else {
        print("Unknown animal type.")
    }
}

java
class Animal {
    private String name;
    
    public Animal(String name) {
        this.name = name;
    }
    
    public String getName() {
        return name;
    }
}
class Lion extends Animal {
    public void roar() {
        System.out.println("The lion is roaring!");
    }
}
class Elephant extends Animal {
    public void trumpet() {
        System.out.println("The elephant is trumpeting!");
    }
}
public class Main {
    public static void main(String[] args) {
        Animal[] animals = {new Lion("Simba"), new Elephant("Dumbo")};
        
        for (Animal animal : animals) {
            if (animal instanceof Lion) {
                Lion lion = (Lion) animal;
                lion.roar();
            } else if (animal instanceof Elephant) {
                Elephant elephant = (Elephant) animal;
                elephant.trumpet();
            } else {
                System.out.println("Unknown animal type.");
            }
        }
    }
}