when Vue.js is updating the list of rendered elements with v-for, it defaults to the "reuse in place" policy.
if the order of the data items is changed, Vue will not move the DOM elements to match the order of the data items, but simply reuse each element here and ensure that it displays each element that has been rendered under a specific index . this default mode is efficient, but only for list rendered output that does not depend on the subcomponent state or temporary DOM state (for example, form input values).
this paragraph of the document cannot be deeply understood. No, no, no.