如何创建子类对象？

Question

不幸的是，我的代码一次又一次收到错误消息'self' used in property access 'healthPoints' before 'super.init' call：

头等舱单位

import UIKit
import SpriteKit

class Unit {

//    var gameScene : GameScene!

    var healthPoints = 10
    var damage = 5
    var movement = 1

    init(pHealthPoints: Int, pDamage: Int,pMovement: Int) {

        self.healthPoints = pHealthPoints
        self.damage = pDamage
         self.movement = pMovement
    }


    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

}

子类别骑士

import UIKit
import SpriteKit

class Knight: Unit {

    override init(pHealthPoints: Int, pDamage: Int, pMovement: Int) {

        self.healthPoints = pHealthPoints
        self.damage = pDamage
        self.movement = pMovement

    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

}

在子类中我到底要在哪里写super？

如何通过Unit访问类Knight或类GameScene.swift或创建类Knight的对象？< / p>

对于每个答案我都很感谢

Answer 1

您只需要调用super.init，然后再将任何值分配给子类的属性。也无需实现init?(coder aDecoder: NSCoder)。还请记住，您重写的init方法实际上与超级实现没有任何不同，因此没有必要对其进行覆盖。

class Knight: Unit {

    override init(pHealthPoints: Int, pDamage: Int, pMovement: Int) {
        super.init(pHealthPoints: pHealthPoints, pDamage: pDamage, pMovement: pMovement)
        self.healthPoints = pHealthPoints
        self.damage = pDamage
        self.movement = pMovement
    }
}