javascript - 請教：Vue如何刪除選取的陣列元素(有多個選取的情況下)?

Question

資料是模擬的，當點擊編輯的時候，我想刪除選取的元素，就是如果選取一個的情況下，就刪除一個，選取多個的情況下，就刪除多個，這樣
每個陣列裡的元素，預設有個checked 屬性

演示地址

html結構

    <p class="t-root" style="margin-bottom: 1.6rem;">
        <section class="shopping-cart-title" flex f-d="r" f-w="n" j-c="s-b" a-i="center">
            <p>全部商品</p>
            <p>
                <a href="javascript:;" @click="editorShopping">{{ showtext ? '编辑' : '完成' }}</a>
            </p>
        </section>

        <!-- 购物车商品列表 -->
        <section class="shopping-list">
         <template v-if="shoppingList.length > 0">
            <p v-for="(shopping,index) in shoppingList" class="item" flex f-d="r" f-w="n" j-c="s-b" a-i="center">
                <p class="shopping-checkbox">
                    <input :id="shopping.id" type="checkbox" name="" class="" v-model="shopping.checked">
                    <label :for="shopping.id"></label>
                </p>
                <p class="shopping-box" flex f-d="r" f-w="n" j-c="start" a-i="center">
                    <p><img :src="shopping.imgsrc" alt=""></p>
                    <p class="info">
                        <h3>{{ shopping.title }}</h3>
                        <p class="acount" flex f-d="r" f-w="n" j-c="s-b" a-i="center">
                            <span class="money">￥{{ shopping.money }}</span>
                            <p class="count" flex f-d="r" f-w="n" j-c="center" a-i="center">
                                <span class="shopping-num" v-show="showtext">x{{ shopping.shoppingnum }}</span>
                                <p flex f-d="r" f-w="n" j-c="center" a-i="center" v-show="!showtext">
                                    <span class="minus" :class="{active : shopping.shoppingnum > 1}" @click="reduce(index)">
                                    <i class="icon iconfont icon-t-icon8"></i>
                                    </span>
                                    <input type="text" readonly disabled class="showNumber" v-model="shopping.shoppingnum">
                                    <span class="add" :class="{active : shopping.shoppingnum < 100}" @click="add(index)">
                                    <i class="icon iconfont icon-t-icon7"></i>
                                    </span>
                                 </p>
                            </p>
                        </p>
                    </p>
                </p>
            </p>
         </template>

        </section>


        <section class="download-order-footer" flex f-d="r" f-w="n" j-c="s-b" a-i="center">
            <p class="shopping-checkall">
                <input id="checkall" type="checkbox" class="" name="">
                <label for="checkall">
                    <i>全选</i>
                </label>
            </p>
            <p class="left">
                总计：<b>￥684</b>
            </p>
            <p class="right">
                <a href="javascript:;" flex f-d="r" f-w="n" j-c="center" a-i="center" v-show="showtext">去付款</a>
                <a @click="removeShopping" href="javascript:;" flex f-d="r" f-w="n" j-c="center" a-i="center" v-show="!showtext">删除</a>
            </p>
        </section>

    </p>

js程式碼

#

    var vm = new Vue({
        el : ".t-root",
        data : {
            showtext : true,
            shoppingList : [
                {
                    id : 11,
                    title : '贡牌茶叶西湖春茶正宗雨前龙井茶礼盒装礼盒装160g礼盒装',
                    money : 48,
                    imgsrc : 'images/download-order-img-11@2x.png',
                    shoppingnum : 1,
                    checked : true
                },
                {
                    id : 22,
                    title : '贡牌茶叶西湖春茶正宗雨前龙井茶礼盒装礼盒装160g礼盒装',
                    money : 98,
                    imgsrc : 'images/download-order-img-11@2x.png',
                    shoppingnum : 1,
                    checked : true
                },
                {
                    id : 33,
                    title : '贡牌茶叶西湖春茶正宗雨前龙井茶礼盒装礼盒装160g礼盒装',
                    money : 148,
                    imgsrc : 'images/download-order-img-11@2x.png',
                    shoppingnum : 1,
                    checked : true
                }
            ]
        },
        computed : {
        },
        methods : {
            editorShopping : function(){
               this.showtext = !this.showtext;
            },
            removeShopping : function(){
                var that = this;
                that.shoppingList.forEach(function(value,index){
                    //只有为true时才删除
                    if (value.checked) {
                        that.shoppingList.splice(index,1);
                       // console.log(index);
                    }
                });
            },
            add : function(index){
                var shopping = this.shoppingList[index];
                if (shopping.shoppingnum == 100) {
                    return false;
                }else {
                    shopping.shoppingnum ++;
                }
            },
            reduce : function(index){
                var shopping = this.shoppingList[index];
                if (shopping.shoppingnum == 1){
                    return false;
                }else {
                    shopping.shoppingnum --;
                }
            }
        }
    });

Answer 1

JS中刪除批量刪除數組元素時應該倒序刪除(意思是先刪除索引大的元素，再刪除索引小的元素)，
因為在刪除的過程中數組的索引會變化，如果先刪除了小的元素，後面元素的索引都會改變.
我寫了個簡單的demo:

<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8">
        <title></title>
    </head>
    <body>
        <p id="app">
            <p>
                <button @click="removeAll">删除全部</button>
            </p>
            <ul v-for="value of arr">
                <li>
                    {{value}}
                </li>
            </ul>
        </p>
    </body>
    <script src="./vue.js" charset="utf-8"></script>
    <script type="text/javascript">
        new Vue({
            el:'#app',
            data:{
                arr:['a','b','c']
            },
            methods:{
                removeAll:function() {
                    var length = this.arr.length;
                    for(let i =length ;i>=0 ;i--){
                        this.arr.splice(i,1);
                    }
                }
            }
        })
    </script>
</html>

Answer 2

換個思路，別刪除，過濾更簡單直覺。

// 直接过滤更简单，直观
var arr = [{a:1,c:true},{a:2,c:false},{a:3,c:true}]
arr = arr.filter(function(i){ return !i.c })
console.log(arr) // {a:2,c:false}

Answer 3

已經解決了！
參考位址
用逆向循環

            removeShopping : function(){
                 var that = this;
                 for (var i = that.shoppingList.length - 1;i >= 0;i--) {
                     var index = that.shoppingList[i];
                     if (index.checked) {
                         that.shoppingList.splice(i,1);
                     }
                 }
            }