Vite3.0 is released, take a look at the new features of Vite3.0

In Vue3, dependency injection is implemented through provide and inject, supporting data passing across levels. 1. Use provide to provide data or methods in the parent component, and inject is obtained in the child component; 2. Provide responsive state and maintain variability through exposing methods; 3. Use Symbol as key to avoid naming conflicts; 4. Injected values can be used in contexts outside the setup, such as instructions, but make sure that inject has been called in the setup. This mechanism is suitable for plug-in development, theme configuration and global state management, making component communication clearer and more efficient.

Refreshing the page after deploying the Vue project returns 404 because VueRouter's history mode is used but the server is not configured correctly. 1. Confirm whether history mode is used. In this mode, the path such as /about will request resources from the server; 2. Configure the server to redirect all requests to index.html, for example, add try_files$uri$uri//index.html in Nginx, Apache uses .htaccess rules, Vercel or Netlify to set rewrite rules; 3. Check whether the deployment path is correct. If deployed in a subpath, you must set the correct publi in vue.config.js.

Vue's virtual DOMdiff algorithm improves performance by comparing old and new virtual DOM trees to minimize real DOM operations. 1. When the data changes, Vue re-renders the component into a virtual DOM tree, which is a lightweight and fast and operational JavaScript object; 2. Vue uses an O(n) complexity heuristic algorithm to compare new and old virtual DOM trees, and replaces them if the node types are different, and updates attributes if the same ones; 3. When rendering the list, use the key attribute to help Vue accurately track element changes and improves diff efficiency; 4. In the end, Vue will batch update the difference to the real DOM, reducing the number of re-arranged and redrawings, thereby maintaining the efficient response of the interface.

InVue,awatcherisusedtoreacttodatachanges,especiallyforperformingsideeffects.WatchersareidealforactionslikeAPIcallsorUIupdatesinresponsetodatachanges,unlikecomputedpropertieswhichareforderivingvalues.Tosetupawatcher,defineitinthewatchoptionofacomponen

Vue3's responsive conversion simplifies the use of responsive data by automatically unpacking refs. 1. It allows direct use of ref variables in contexts such as template expressions, watch, and computed without the need for .value; 2. After enabling this feature, the deconstructed defineProps() value remains responsive; 3. Applicable only to environments configured with and specific build tool; 4. Not applicable to non-primitive values such as objects or arrays. This feature reduces redundant code and improves the development experience, but may reduce code clarity. Whether it is enabled depends on project requirements and team preferences.

Using slots and named slots in Vue can improve component flexibility and reusability. 1. The slot allows the parent component to insert content into the child component through a tag, such as inserting paragraph text into the Card.vue component; 2. The named slot realizes control of the content insertion position through the name attribute, such as defining the header, body and footer areas respectively in the modal box component; 3. The default content can be set in the slot as an alternative when the parent component is not provided, such as the default close button; 4. The # symbol is the abbreviation syntax of v-slot:; 5. It is recommended to use slots reasonably to avoid excessive dependence, and some content can be considered to be implemented through props or scope components.

In Vue.js, the DOM can be accessed through ref and lifecycle hooks. Use the ref attribute to get element references, such as accessing through this.$refs.myInput in mounted; 1. It is recommended to operate the DOM in mounted or updated life cycle; 2. Using ref in v-for will return an element array; 3. Using ref for components will get component instances, and DOM nodes need to be obtained through $el; 4. Avoid excessive use of ref, give priority to data binding, and only operate the DOM directly if necessary.

The solution to the error "JavaScripttheapoutofmemory" in the Vue project packaging error is as follows: 1. Increase the Node.js memory limit, use the --max-old-space-size parameter to increase the memory limit, such as node--max-old-space-size=4096vue-cli-servicebuild, and configure scripts in package.json; 2. Check dependencies and plug-ins to avoid introducing large libraries, closing production environment sourcemap, and optimizing loader configuration; 3. Enable webpack subcontracting mechanism, configure splitCh in vue.config.js