const DATA = {
    list: [
        {
            name: '第1项',
            checked: false,
            num: 1,
            price: 100,
        },
        {
            name: '第2项',
            checked: false,
            num: 2,
            price: 650,
        },
        {
            name: '第3项',
            checked: false,
            num: 5,
            price: 300,
        }
    ]
}


new Vue({
    el: '.app',
    data: {
        list: []
    },
    computed: {
        selectedItem() {
            return this.list.filter(item => item.checked)
        },
        selectedCount() {
            return this.selectedItem.reduce((pre, cur) => pre + cur.num, 0)
        },
        selectedPrice() {
            return this.selectedItem.reduce((pre, cur) => pre + cur.num * cur.price, 0)
        }
    },
    filters: {
        toPrice(fen) {
            return (fen / 100).toFixed(2)
        }
    },
    created() {
        this.list = DATA.list
    }
})