卡牌RPG游戏读取Enemy/speed属性时出现TypeError问题求助

点击Attack按钮时，本该读取玩家与敌人的speed属性判断攻击顺序，却持续触发以下错误：

Uncaught TypeError: Cannot read properties of undefined (reading 'speed')
    at Object.calcAttack (Player.js:18:28)
    at HTMLButtonElement.onclick ((index):34:64)
calcAttack @ Player.js:18
onclick @ (index):34

相关代码 #

Index.HTML #

<button onclick="playerMoves.calcAttack()">Attack!
</button>

Player.JS #

let player;

function Player(level, health, attack, speed, magic, experience){
    this.level = level;
    this.health = health;
    this.attack = attack;
    this.speed = speed;
    this.magic = magic;
    this.experience = experience;
};

let playerMoves =  {
    calcAttack: function(){
        // 攻击顺序逻辑：获取玩家和敌人速度判断先手
        let playerSpeed = player.speed;
        let enemySpeed = enemy.speed;

        console.log(playerSpeed, enemySpeed);
        
        if (playerSpeed >= enemySpeed){
            enemy.health = enemy.health - outputDmg;

            if(enemy.health <= 0){
                alert("你击败了敌人！");
                // 加载新敌人的函数
            } else{
                player.health = player.health - outputEnemyDmg;

                if(player.health <= 0){
                    alert("你阵亡了")
                }
            };
        }    
    }
}

Enemy.JS #

function Enemy(rank, name, imgName, health, attack, speed, droppedExp){
    this.rank = rank;
    this.name = name;
    this.imgName = imgName;
    this.health = health;
    this.attack = attack;
    this.speed = speed;
    this.droppedExp = droppedExp;
};

// 敌人等级分为E、D、C、B、A、S，对应数值1-6
let goblin = new Enemy(1,"哥布林", "goblin", 50, 5, 10, 10);
let raikan = new Enemy(1, "钢牙雷坎", "raikan", 50, 5, 10, 10);
let briga = new Enemy(1, "利爪布里加", "briga", 55, 15, 10, 10);
let centipede = new Enemy(2 ,"巨型沙漠蜈蚣", "centipede", 100, 15, 5, 20);
let jackal = new Enemy(2, "地牢豺狼", "jackal", 75, 10, 15, 20);

问题原因 #

错误核心是player或enemy变量未被正确赋值：

• player仅声明但未通过new Player()创建具体实例，调用player.speed时自然找不到属性；
• Enemy.js里定义了多个敌人实例，但calcAttack函数中直接使用的enemy变量未指向任何已创建的敌人对象，属于未定义状态。

修复步骤 #

1. 创建玩家实例：在Player.js中添加玩家初始化代码，比如：

// 放在Player函数定义之后
player = new Player(1, 100, 15, 12, 8, 0);

2. 绑定当前战斗敌人：

   • 全局声明currentEnemy变量，进入战斗时赋值为选中的敌人，比如：

     // 比如选择哥布林作为当前敌人
     let currentEnemy = goblin;
     

   • 修改Player.js的calcAttack函数，把所有enemy替换为currentEnemy：

     let enemySpeed = currentEnemy.speed;
     currentEnemy.health = currentEnemy.health - outputDmg;
     

3. 补充伤害变量定义：代码中outputDmg和outputEnemyDmg未定义，需要补充伤害计算逻辑，比如：

// 在calcAttack函数内添加
let outputDmg = player.attack; // 简化的玩家伤害计算
let outputEnemyDmg = currentEnemy.attack; // 简化的敌人伤害计算

内容的提问来源于stack exchange，提问作者Alejandro Garcia Baltazar