设计模式之外观模式(一)

class Sum {
    sum(a,b){return a+b}
}
class Minus {
    minus(a,b){return a-b}
}
class Multiplay {
    multiplay(a,b){return a*b}
}
class Divide{
    divide(a,b){return a/b}
}

class Calculation{
    constructor(){
        this.sum1 = new Sum()
        this.minus1 = new Minus()
        this.multiplay1 = new Multiplay()
        this.divide1 = new Divide()
    }
    sum(a,b){
       return this.sum1.sum(a,b)
    }
}
let a = new Calculation()
console.log(a.sum2(1,2))