将数字转换为人民币单位格式

[metroluffy]

请根据面向对象编程的思想，设计一个类型 Cash用于表达人民币，使得：

class Cash {
}
const cash1 = new Cash(105)
const cash2 = new Cash(66)
const cash3 = cash1.add(cash2)
const cash4 = Cash.add(cash1, cash2)
const cash5 = new Cash(cash1 + cash2)

console.log(`${cash3}`, `${cash4}`, `${cash5}`)
// 1元7角1分 1元7角1分 1元7角1分

[metroluffy]

class Cash {
    #money = 0
    constructor(money = 0) {
        if(typeof money !== 'number') throw new Error('请输入数值')
        this.#money = money 
    }

    get money() {
        return this.#money
    }

    add(money  = 0){
        if(money instanceof Cash) {
            money = money.money 
        } else if(typeof money !== 'number') throw new Error('请输入数值')
        return Cash.trans(this.#money + money)
    }

    static add(money  = 0, money2 = 0) {
        if(money instanceof Cash) {
            money = money.money 
        }
        if(money2 instanceof Cash) {
            money2 = money2.money 
        } 
        if(typeof money !== 'number' || typeof money2 !== 'number') throw new Error('请输入数值')
        return Cash.trans(money + money2)
    }

    static trans(money = 0) {
        if(money === 0) return '0元'
        let res =  ''
        const symb = ['分', '角', '元']
        for (let i = 0; i < symb.length; i++) {
            const t = (i === 2 ? money : money % 10)
            res =  (t === 0 ? '' : (t + symb[i])) + res
            money = Math.floor(money / 10)
        }
        return res
    }

    valueOf() {
        return this.#money
    }

    toString() {
        return Cash.trans(this.#money)
    }
}