vue学习(五)基础入门-基础知识(9)-JavaScript高阶函数

迷南。 2023-05-29 09:16 18阅读 0赞

几种for语法

用的是前面购物车案例的代码

[购物车小案例][Link 1]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d1eXhpbnU_size_16_color_FFFFFF_t_70][]

将普通函数转换成JavaScript高阶函数和

![20191105154549885.png][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d1eXhpbnU_size_16_color_FFFFFF_t_70 1][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d1eXhpbnU_size_16_color_FFFFFF_t_70 2][]

链式编程

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d1eXhpbnU_size_16_color_FFFFFF_t_70 3][]

箭头函数

![20191105155013814.png][]

表单绑定 v-model

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d1eXhpbnU_size_16_color_FFFFFF_t_70 4][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d1eXhpbnU_size_16_color_FFFFFF_t_70 5][]

双向绑定的原理

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d1eXhpbnU_size_16_color_FFFFFF_t_70 6][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d1eXhpbnU_size_16_color_FFFFFF_t_70 7][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d1eXhpbnU_size_16_color_FFFFFF_t_70 8][]

v-model 结合 radio

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d1eXhpbnU_size_16_color_FFFFFF_t_70 9][]

![20191105161849518.png][]

v-model 结合CheckBox

lable好处就是用户可以点击文字也会选中

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d1eXhpbnU_size_16_color_FFFFFF_t_70 10][]

![20191105162642785.png][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d1eXhpbnU_size_16_color_FFFFFF_t_70 11][]

![20191105163031679.png][]

v-model :select

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d1eXhpbnU_size_16_color_FFFFFF_t_70 12][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d1eXhpbnU_size_16_color_FFFFFF_t_70 13][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d1eXhpbnU_size_16_color_FFFFFF_t_70 14][]

v-model双向绑定数组数据时遇到的天坑

<body>
        <div id ="app"> 
            <input type="checkbox" value="篮球"  v-model="hobbies">篮球
            <input type="checkbox" value="羽毛球"  v-model="hobbies">羽毛球
            <input type="checkbox" value="兵乓球"  v-model="hobbies">兵乓球
            <input type="checkbox" value="足球"  v-model="hobbies">足球
    
            <h2>您的爱好是：{
       {hobbies}}</h2>
    
            <label v-for="item in originHobbies" :for="item">
                <input type="checkbox" :value="item" :id="item" v-model="hobbies">{
       {item}}
            </label>
            
        </div>
    
        <script>
         //创建Vue实例,得到 ViewModel
         var vm = new Vue({
            el: '#app',
            data: {
                url:'<a href="http://www.baidu.com">百度一下</a>',
    
                hobbies: [],
                originHobbies:['篮球', '足球', '台球', '高尔夫球', '羽毛球'],
            },
            
            methods: {}
         });
        </script>
    </body>

用Chrome浏览器

![20191105205827922.png][]

用360浏览器

![20191105205848167.png][]

查看了几个文档后发现是Chrome不兼容Object.observe

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d1eXhpbnU_size_16_color_FFFFFF_t_70 15][]

## 解决方法 ##

使用 `Vue.set(object, key, value)` 方法将响应属性添加到嵌套的对象上。 还可以使用 `vm.$set` 实例方法，这也是全局 `Vue.set` 方法的别名。

[vue中遇到的坑 --- 变化检测问题（数组相关）][vue_ ---]

[深入响应式原理][Link 2]

也就是说，因为360浏览器太老（没有更新）的原因，没有废弃object.server，所以才能够这样用。现阶段只能使用vue.set

修饰符

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d1eXhpbnU_size_16_color_FFFFFF_t_70 16][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d1eXhpbnU_size_16_color_FFFFFF_t_70 17][]

[Link 1]: https://blog.csdn.net/wuyxinu/article/details/102912430
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[20191105154549885.png]: https://img-blog.csdnimg.cn/20191105154549885.png
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[20191105162642785.png]: https://img-blog.csdnimg.cn/20191105162642785.png
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[20191105205827922.png]: https://img-blog.csdnimg.cn/20191105205827922.png
[20191105205848167.png]: https://img-blog.csdnimg.cn/20191105205848167.png
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[vue_ ---]: https://www.cnblogs.com/zhuzhenwei918/p/6893496.html
[Link 2]: https://cn.vuejs.org/v2/guide/reactivity.html
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