<ul> <li><b>attribute use :key</b> <p>It's no longer required to indicate a key for instructions <code>v-if/v-else/v-else-if</code> – Vue does it automatically.</p> <p>You won't be able to indicate keys manually, but each key must have a unique name.</p> <p>When using the tag <code><template></code> with iterator <code>v-for</code>, the key must be located on this tag instead of its children, as before.</p> <p>Before:</p> <p><pre class="syntax mh-100"> <template v-for="item in list"> <div :key="'heading-' + item.id">...</div> <span :key="'content-' + item.id">...</span> </template> </pre></p> <p>Now:</p> <p><pre class="syntax mh-100"> <template v-for="item in list" :key="item.id"> <div>...</div> <span>...</span> </template> </pre></p> <p>You can read more about such this update in the <a href="https://v3-migration.vuejs.org/breaking-changes/key-attribute.html" target="_blank">migration guide</a>.</p> </li> <li><b>using instruction v-if jointly with v-for</b> <p>Now <code>v-if</code> has the priority when using <code>v-if</code> jointly with <code>v-for</code> at a single element.</p> </li> <li><b>using instruction v-model</b> <p>If you have used the instruction <code>v-model</code>, you must read the article about the key changes in the <a href="https://v3-migration.vuejs.org/breaking-changes/v-model.html" target="_blank">migration guide</a>.</p> </li> </ul> <br/><br/>