需要帮助修复类中的一个小方法

Question

我不确定为什么这不起作用，逻辑对我来说看起来不错。我希望更有经验的眼睛可以提供一些建议。这应该将_grit 返回为1。但它返回0。如果我创建gainedToughness(8)，_grit 返回4，它应该返回3。

class Person {
    constructor(name, age, profession){
        this._name = name;
        this._age = age;
        this._profession = profession;
        this._health = 100;
        this._grit = 0;
    }
    get name() {
        return this._name;
    }
    get age() {
        return this._age;
    }
    get profession() {
        return this._profession;
    }
    gotInjured(damageNum){
        const weaker = this._health -= damageNum;
        return weaker;
    }
    gainedToughness(damageNum){.           <---------------------------
        let grittier = this._grit++;
        let lotGrittier = this._grit += 3;
        return damageNum <= 5 ? grittier : lotGrittier; 
    }
}

const donRickles = new Person('donRickles', 33, 'comedian');

console.log(donRickles.gotInjured(1));
console.log(donRickles.gainedToughness(1));      <-----------

Answer 1

您对++ 和+= 的使用导致了您的问题。因为它们都是为重新分配变量而设计的，这不是你想要的。

class Person {
    constructor(name, age, profession){
        this._name = name;
        this._age = age;
        this._profession = profession;
        this._health = 100;
        this._grit = 0;
    }
    get name() {
        return this._name;
    }
    get age() {
        return this._age;
    }
    get profession() {
        return this._profession;
    }
    gotInjured(damageNum){
        const weaker = this._health -= damageNum;
        return weaker;
    }
    gainedToughness(damageNum){
        let grittier = this._grit + 1;
        let lotGrittier = this._grit + 3;
        return damageNum <= 5 ? grittier : lotGrittier; 
    }
}

const donRickles = new Person('donRickles', 33, 'comedian');

console.log(donRickles.gotInjured(1));
console.log(donRickles.gainedToughness(1));
console.log(donRickles.gainedToughness(8));

如果您想更新属性值并返回新值，请执行以下操作：

class Person {
    constructor(name, age, profession){
        this._name = name;
        this._age = age;
        this._profession = profession;
        this._health = 100;
        this._grit = 0;
    }
    get name() {
        return this._name;
    }
    get age() {
        return this._age;
    }
    get profession() {
        return this._profession;
    }
    gotInjured(damageNum){
        const weaker = this._health - damageNum;
        this._health = weaker;
        return this._health;
    }
    gainedToughness(damageNum){
        let grittier = this._grit + 1;
        let lotGrittier = this._grit + 3;
        this._grit = damageNum <= 5 ? grittier : lotGrittier; 
        return this._grit;
    }
}

const donRickles = new Person('donRickles', 33, 'comedian');

console.log(donRickles._health)
console.log(donRickles.gotInjured(1));
console.log(donRickles._health)

console.log(donRickles._grit)
console.log(donRickles.gainedToughness(1));
console.log(donRickles._grit)