What are the css target selectors?

Common problems with Vue responsive systems include: 1. Directly adding object properties does not trigger updates, and attributes need to be defined in advance; 2. Array subscript assignment does not update the view, $set or mutation methods such as splice should be used; 3. After deconstructing nested objects, they do not track them, and they need to be modified through the original path; 4. Accessing the DOM without completing asynchronous update causes old values to be read, and $nextTick should be used to wait for updates. Mastering the solutions to these problems can effectively avoid responsive traps.

The front-end construction process is a process of converting development code into an efficient browser running form, including code compilation, module packaging, resource optimization, and version control. Common processes include: 1. Code compilation such as TypeScript to JS; 2. Module packaging and merging files; 3. Compressing JS, CSS, and image optimization; 4. Automatic hash to prevent cache. Mainstream tools such as Webpack and Vite each have their own focus, and their configuration includes entry, output, loader, and plug-ins. Build a separate development and production model. The former is hot update without compression, while the latter is compressed with TreeShaking. Common problems include module path errors, package size is too large, syntax support and image processing problems. Debugging can pass error message, dist structure checking, and sourc

The key to implementing animations using Vue.js' Transition component is to understand its working mechanism and class name rules. Transition component is suitable for the entry, departure and update status of elements, and realizes fading or sliding effects by wrapping elements and matching CSS class names; for example, wrapping elements controlled by v-if, and defining classes such as fade-enter-active, fade-leave-active, etc. to control transition time and styles; entry animations are triggered sometimes when elements are from scratch, and exit animations are triggered when elements are about to be hidden or destroyed; for list animations, they should be used, specify keys for each element and set tag attributes to render them into target tags, and support sorting animations, through .lis

The choice of GitHubActions or GitLabCI depends on the platform where the code repository is located. If it is on GitHub, choose GitHubActions. If it is on GitLab, use GitLabCI. Both can realize core functions such as automatic construction, testing and deployment. 1. Platform matching: GitHub project uses GitHubActions more natural, while GitLab project uses GitLabCI more convenient, and their integration is more convenient for permission management; 2. Configuration method: Both are based on YAML, but the keywords are different, such as GitHub uses jobs and steps, and GitLab uses script; 3. Deployment process: GitHubActions has

The core of optimizing front-end build time is to reduce redundant work, improve processing efficiency, utilize caches and select efficient tools. 1. Use TreeShaking and code segmentation reasonably to ensure that it is introduced on demand and dynamic import reduces the packaging volume; 2. Reduce unnecessary loader processing, exclude node_modules, upgrade loaders and relax the scope of Babel translation; 3. Use the caching mechanism to speed up repeated construction, enable Webpack cache, CI cache and use offline installation; 4. Upgrade toolchain, such as using Vite, esbuild or Rollup to improve the construction speed, although there is migration cost, it has significant effect.

Block-level elements occupy one line by default and support full width, while inline elements are displayed in text streams without line breaks. 1. Block-level elements such as, etc. can automatically wrap and width and height can be set; 2. Inline elements such as, etc. are embedded in text streams, width and height settings are usually invalid; 3. The element type can be changed through the display attribute of CSS, such as block, inline-block or flex; 4. Some elements such as and containers using Flexbox/Grid have mixed behavior. Mastering these helps to build a more controllable page layout.

Use Mocha and Chai to test JavaScript first to install these two libraries. 1. The installation method is npminstall--save-devmochachai, and create a test folder in the project root directory to store the test files; 2. Configure npmscript such as "scripts":{"test":"mocha"} to start the test through npmtest; 3. Use describe and it to organize the structure of the test cases, and write assertions in combination with expect; 4. Chai supports expect, should and assert, and recommend expe

SVGstandsforScalableVectorGraphics,anXML-basedformatthatusesmathematicalformulasinsteadofpixelstodisplayimagesontheweb.1.SVGsstaysharpatanysize,makingthemidealforlogos,icons,andscalablegraphics.2.Theycanbeeditedwithtexteditors,styledwithCSS,andmanipu