lovecoding
/
W260426


			
				
					
						
						
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							<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="./js/vue.js"></script>
</head>
<body>
    <div id="app">
        <h1>商品单价：{{price}}</h1>
        <div>购买数量：<input type="number" v-model="num"></div>
        <h1>{{msg}}</h1>
        <h1>商品总价：{{totalPrice}}</h1>
        <h1>会员9折后价格：{{memberPrice}}</h1>
    </div>
    <script>
        new Vue({
            el: '#app',
            data: {
                price:200,
                num:0,
                msg:"还剩余10件"
            },
            computed:{
                totalPrice(){
                    return this.price*this.num;
                },
                memberPrice(){
                    return this.totalPrice*0.9;
                }
                
            },
            watch:{
                num(newVal,oldVal){
                    if(newVal<0){
                        this.num = 0;
                    }else if(newVal>10){
                        this.msg= "购买数量不能超过10件";
                        // this.num = 10;
                    }else{
                        this.msg="还剩余"+(10-newVal)+"件"
                    }
                }
            }
        })
    </script>
</body>
</html>