What are functional components in Vuejs explain with example? 073

 What are functional components in Vuejs explain with example?

Functional components in Vue.js are a component type that focuses primarily on rendering the UI without managing any internal state or instance lifecycle hooks. They offer a more concise and declarative approach to building components, especially for simpler UI elements.

Key Characteristics:

• Pure Functions: They are essentially JavaScript functions that accept props as input and return JSX-like virtual DOM structures.

• No State: They don't have their own internal state (data, computed properties, watchers).

• No Lifecycle Hooks: They don't have access to Vue's lifecycle hooks like created, mounted, etc.

• Single-File Components: Can be defined using the <script setup> syntax in single-file components (SFCs).

Example:

Code snippet

<script setup>
function HelloWorld({ name }) {
  return <h1>Hello, {name}!</h1>;
}
</script>

<template>
  <HelloWorld name="Vue" />
</template>

Advantages:

• Readability: Often lead to cleaner and more concise code, especially for presentational components.

• Performance: Can potentially have minor performance benefits due to less overhead.

• Reusability: Easier to create reusable UI elements without managing state or lifecycle.

• Testability: Generally easier to test.

When to Use:

• Presentational Components: Simple components that primarily render UI based on props.

• Reusable UI Elements: Components that render common UI patterns without complex logic.

• Code Organization: Breaking down larger components into smaller, more manageable parts.

When to Avoid:

• Stateful Components: Components that need to manage their own internal state or react to lifecycle events.

• Logic-Heavy Components: Components with complex logic or interactions.

Considerations:

• Composition API: Often used in conjunction with the Composition API for managing logic and state outside of components.

• Single-File Components: Require the <script setup> syntax in SFCs.

• Trade-offs: Balance readability, maintainability, and flexibility when choosing between functional and regular components.