swift的类class

2024-11-21

定义类

class Enemy{
    var health = 100
    var attackStrength = 10
    
    func move(){
        print("Walk forward")
    }
    
    func attack(){
        print("Land a hit, does \(attackStrength) damage.")
    }
}

继承类

class Dragon: Enemy {
    var wingSpan = 2
    
    func talk(speech: String){
        print("Says: \(speech)")
    }
    
    override func move() {
        print("Fly forward")
    }
    
    override func attack() {
        super.attack()
        print("Spits fire, does 10 damage")
    }
}

使用类

let skeleton = Enemy()
print(skeleton.health)
skeleton.move()
skeleton.attack()

let dragon = Dragon()
dragon.wingSpan = 5
dragon.attackStrength = 15
dragon.talk(speech: "My teeth are swords! My claws are spears! My wings are a hurricane")
dragon.move()
dragon.attack()

苹果的UI class

swift的struct和class的区别

1. struct不能继承，class可以。
2. class需要init()，即self.health=health，struct不需要init()。
3. struct修改property时，需要mutating func，而class不用。
4. class是浅拷贝，s2=s1会对应同一个对象；stuct是深拷贝，不会互相影响。

因为安全拷贝的原因，苹果推荐优先使用Struct，可以参考Choosing Between Structures and Classes