观察属性$watch

<!DOCTYPE html>

<html lang="zh">

<head>

    <title></title>

    <meta charset="UTF-8">

    <meta name="viewport" content="width=device-width, initial-scale=1">

    <script src="https://unpkg.com/vue/dist/vue.js"></script>

    <link href="../css/style.css" rel="stylesheet"> </head>

<body>

<div id="myApp">

    <p>今年3月3日发卖的任天堂新一代主机Switch的价格是：{{price}}円，含税价格为：{{priceInTax}}円，折合人民币为：{{priceChinaRMB}}元。</p>

    <button @click="btnClick(10000)">加价10000円</button>

</div>

<script>

    var myApp = new Vue({

        el: '#myApp',

        data: {

            price: 0,

            priceInTax: 0,

            priceChinaRMB: 0,

        },

        watch: {

            price: function(newVal, oldVal){

                console.log(newVal, oldVal);

                this.priceInTax = Math.round(this.price * 1.08);

                this.priceChinaRMB = Math.round(this.priceInTax / 16.75);

            },

        },

        methods: {

            btnClick: function(newPrice){

                this.price += newPrice;

            },

        },

    });

    myApp.price = 29980;

</script>

</body>

</html>
myapp

观察属性$watch
