@@ -548,6 +548,57 @@ On those a default key should not be provided.
1. Properties in a Vue Component:
Check [order of properties in components rule][vue-order].
#### `:key`
When using `v-for` you need to provide a *unique*`:key` attribute for each item.
1. If the elements of the array being iterated have an unique `id` it is advised to use it:
```html
<div
v-for="item in items"
:key="item.id"
>
<!-- content -->
</div>
```
1. When the elements being iterated don't have a unique id, you can use the array index as the `:key` attribute
```html
<div
v-for="(item, index) in items"
:key="index"
>
<!-- content -->
</div>
```
1. When using `v-for` with `template` and there is more than one child element, the `:key` values must be unique. It's advised to use `kebab-case` namespaces.
```html
<templatev-for="(item, index) in items">
<span:key="`span-${index}`"></span>
<button:key="`button-${index}`"></button>
</template>
```
1. When dealing with nested `v-for` use the same guidelines as above.
