If you like my articles, you can buy me a coffee :)
Buy me coffee
Vue.js Conditional Rendering
v-if and v-show directives are used to conditionally render a block in Vue.js.
v-if
In vue.js, the directive v-if is used to conditionally render a block. The block will only be rendered if the directive's expression returns a truthy value.
Example :
<script setup> import { ref } from 'vue' const show = ref(true) </script> <template> <button>toggle</button> <h1 id="Vue-js">Vue.js</h1> </template>
You can use the v-else directive to indicate an "else block" for v-if. If the v-if directive expression does not return true, v-else block is rendered.
<script setup> import { ref } from 'vue' const show = ref(true) </script> <template> <button>toggle</button> <h1 id="v-if-directive"> v-if directive </h1> <h1 id="v-else-directive"> v-else directive </h1> </template>
v-else-if
The v-else-if, serves as an "else if block" for v-if. It can also be chained multiple times. When v-if and v-else-if do not evaluate to true, the v-else directive is triggered.
<p v-if="currentState === 0">State 0: Message 1</p> <p v-else-if="currentState === 1">State 1: Message 2</p> <p v-else-if="currentState === 2">State 2: Message 3</p> <p v-else>State 3: Message 4</p>
v-show
When we want to display an item conditionally, we can use the v-show directive as another option.
<h1 id="Ok">Ok!</h1>
The difference is that an element with a v-show is always rendered and remains in the DOM. v-show changes the CSS display property to show or hide the element. v-show doesn't work with v-else
v-if vs. v-show
v-if is "real" conditional rendering because it ensures that event listeners and child components inside the conditional block are properly destroyed and re-created during toggles.
v-if : if the condition is false on initial render, it will not do anything - the conditional block won't be rendered until the condition becomes true for the first time.
v-show is always rendered and remains in the DOM. v-show changes the CSS display property to show or hide the element. v-show doesn't work with v-else
v-if has higher toggle costs while v-show has higher initial render costs. prefer v-show if you need to toggle something very often, and prefer v-if if the condition is unlikely to change at runtime.
Conclusion
In this article, we examined the features and differences of v-if and v-show directives. Understanding these distinctions is essential for optimizing rendering performance and managing element visibility in your Vue.js applications.
The above is the detailed content of Vue.js Conditional Rendering and V-if vs V-show. For more information, please follow other related articles on the PHP Chinese website!

JavaScript is widely used in websites, mobile applications, desktop applications and server-side programming. 1) In website development, JavaScript operates DOM together with HTML and CSS to achieve dynamic effects and supports frameworks such as jQuery and React. 2) Through ReactNative and Ionic, JavaScript is used to develop cross-platform mobile applications. 3) The Electron framework enables JavaScript to build desktop applications. 4) Node.js allows JavaScript to run on the server side and supports high concurrent requests.

Python is more suitable for data science and automation, while JavaScript is more suitable for front-end and full-stack development. 1. Python performs well in data science and machine learning, using libraries such as NumPy and Pandas for data processing and modeling. 2. Python is concise and efficient in automation and scripting. 3. JavaScript is indispensable in front-end development and is used to build dynamic web pages and single-page applications. 4. JavaScript plays a role in back-end development through Node.js and supports full-stack development.

C and C play a vital role in the JavaScript engine, mainly used to implement interpreters and JIT compilers. 1) C is used to parse JavaScript source code and generate an abstract syntax tree. 2) C is responsible for generating and executing bytecode. 3) C implements the JIT compiler, optimizes and compiles hot-spot code at runtime, and significantly improves the execution efficiency of JavaScript.

JavaScript's application in the real world includes front-end and back-end development. 1) Display front-end applications by building a TODO list application, involving DOM operations and event processing. 2) Build RESTfulAPI through Node.js and Express to demonstrate back-end applications.

The main uses of JavaScript in web development include client interaction, form verification and asynchronous communication. 1) Dynamic content update and user interaction through DOM operations; 2) Client verification is carried out before the user submits data to improve the user experience; 3) Refreshless communication with the server is achieved through AJAX technology.

Understanding how JavaScript engine works internally is important to developers because it helps write more efficient code and understand performance bottlenecks and optimization strategies. 1) The engine's workflow includes three stages: parsing, compiling and execution; 2) During the execution process, the engine will perform dynamic optimization, such as inline cache and hidden classes; 3) Best practices include avoiding global variables, optimizing loops, using const and lets, and avoiding excessive use of closures.

Python is more suitable for beginners, with a smooth learning curve and concise syntax; JavaScript is suitable for front-end development, with a steep learning curve and flexible syntax. 1. Python syntax is intuitive and suitable for data science and back-end development. 2. JavaScript is flexible and widely used in front-end and server-side programming.

Python and JavaScript have their own advantages and disadvantages in terms of community, libraries and resources. 1) The Python community is friendly and suitable for beginners, but the front-end development resources are not as rich as JavaScript. 2) Python is powerful in data science and machine learning libraries, while JavaScript is better in front-end development libraries and frameworks. 3) Both have rich learning resources, but Python is suitable for starting with official documents, while JavaScript is better with MDNWebDocs. The choice should be based on project needs and personal interests.


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

PhpStorm Mac version
The latest (2018.2.1) professional PHP integrated development tool

SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

Zend Studio 13.0.1
Powerful PHP integrated development environment

Notepad++7.3.1
Easy-to-use and free code editor

SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.