---
url: https://sugarat.top/coding/js/equalA.md
---

# 如何实现变量a同时等于多个值

通过重新定义对象的隐式转换行为实现

如对隐式转换不了解，推荐阅读[类型转换](./../../bigWeb/js/typeConvert.md)

```js
if(a==1&&a==2){
    console.log('yes')
}
```

## 定义\[ToPrimitive]

```js
let a = {
    v:1,
    [Symbol.toPrimitive](){
        return this.v++
    }
}
```

## 定义valueOf

```js
let a = {
    v:1,
    valueOf(){
        return this.v++
    }
}
```

## 定义toString

```js
let a = {
    v:1,
    toString(){
        return this.v++
    }
}
```