$refs: get the element object or sub component instance in the component:

1. In some cases , We want to get the element object or sub component instance directly in the component ：

•   stay Vue In development, we are ... is not recommended DOM operation Of ;
• At this time , We can Bind an element or component with a ref Of attribute attribute ;

The component instance has a $refs attribute ：

He has an object Object, Hold the registration ref attribute All of the DOM Element and component instances ;