1.在做vue的前端时候遇到一个子组件props属性异常的问题，代码如下：
props:{
items:{
type:Array,
default: []
// defaultt: function () { return [] }
}
}
这样定义以后，浏览器的console中出现以下异常
vue.runtime.esm.js?2b0e:619 [Vue warn]: Invalid default value for prop "items": Props with type Object/Array must use a factory function to return the default value.
found in
---> <TabItem> at src/views/search_item/components/tabItem.vue
<ElMain> at packages/main/src/main.vue
<ElContainer> at packages/container/src/main.vue... (1 recursive calls)
<ElTabPane> at packages/tabs/src/tab-pane.vue
<ElTabs> at packages/tabs/src/tabs.vue
<ElMain> at packages/main/src/main.vue
<SearchItemCategory> at src/views/search_item/components/search_item_category.vue
<ElContainer> at packages/container/src/main.vue... (1 recursive calls)
<Index> at src/views/search_item/index.vue
<AppMain> at src/layout/components/AppMain.vue
<Layout> at src/layout/index.vue
<App> at src/App.vue
<Root>
当时看了就感觉很奇怪，所以按照它说的，将默认值改成肩头函数之后就没有问题了。
props:{
items:{
type:Array,
defaultt: function () { return [] }
},
}
