计算购物车价格Vue

<!DOCTYPE html> 
<html> 
<head> <meta charset="utf-8">
    <title>Vue 示例</title>
</head> 
<body>
    <div id="app" >
       总价{{ prices }}
    </div>
<script src="https://unpkg.com/vue/dist/vue.min.js"></script>
<script>
    var padDate = function(value){
        return value < 10 ? '0' + value :value;
    }
    var app = new Vue({
        el: '#app',
        data: {
            package1: [{
                name: 'iPhone 7',
                price: 7199,
                count:2
            },
            {
                name: 'iPad',
                price: 2888,
                count: 1
            }],
            package2: [{
                name: 'apple',
                price: 3,
                count:6
            },
            {
                name: 'orange',
                price: 4.98,
                count: 20
            }]
        } ,
       computed: {
           prices: function () {
               var prices = 0;
               for (let index = 0; index < this.package1.length; index++) {
                   prices+= this.package1[index].price * this.package1[index].count;
               }
               for (let index = 0; index < this.package2.length; index++) {
                   prices +=this.package2[index].price*this.package2[index].count;
               }
               return prices;
           }
       }
    })
</script>
</body>
</html>
新鲜刺激的东西永远都有，玩之前掂量掂量自己几斤几两