（九）state 的简写方式

class Car {
    constructor(name, price) {
        this.name = name
        this.price = price
        this.a = 1
    }
}
const  c1 = new Car('奔驰', 199)
console.log(c1)

class Car {
    constructor(name, price) {
        this.name = name
        this.price = price
        // this.a = 1
    }
    // 直接赋值，给 Car 的实例对象添加一个属性
    a = 1
}
const  c1 = new Car('奔驰', 199)
console.log(c1)

class Person {
    // 赋值语句
    state = {
        isMood: false
    }

    render() {...}
}

// 渲染组件
ReactDom.render(<Person/>, document.getElmentById('test'))

class Person {
    // 赋值语句
    state = {
        isMood: false
    }

    render() {...}

    // 赋值语句，只能写箭头函数，箭头函数是没有自己的 this 的他就像向外层找，就找到实例的 this
    demo = () => {
        const isMood = this.state.isMood
        this.setState({isMood: !isMood})
    }
}

// 渲染组件
ReactDom.render(<Person/>, document.getElmentById('test'))