SOURCE

class MyCalculator{
    constructor(value){
        this.value = value
    }
    //加
    add(data){
        this.value = this.value + data
        return this
    }
    //减
    minus(data){
        this.value = this.value - data
        return this
    }
    //乘
    multi(data){
        this.value = this.value * data
        return this
    }
    //除
    div(data){
        this.value = this.value / data
        return this
    }
    //除
    pow(data){
        this.value = this.value ** data
        return this
    }
}

const calculator = new MyCalculator(123)
calculator.add(1).minus(2).multi(3).div(4).pow(2)
console.log(calculator.value)