Composable vs Hook in React: Key Differences and Usage

Hooks are built-in React functions to manage state and lifecycle inside functional components, while Composables (in Vue) are reusable functions that encapsulate logic for composition API. In React, hooks enable component behavior reuse, whereas composables in Vue serve a similar role but follow Vue's reactive system.

Quick Comparison

Here is a quick side-by-side comparison of React Hooks and Vue Composables to understand their main traits.

Aspect	React Hook	Vue Composable
Purpose	Manage state and lifecycle inside React components	Encapsulate and reuse reactive logic in Vue components
Usage	Called inside React functional components	Called inside Vue setup() function
Reactivity	Uses React's state and effect system	Uses Vue's reactive and ref system
Return Value	State variables and functions	Reactive references and functions
Scope	Tied to React component lifecycle	Tied to Vue component lifecycle
Flexibility	Built-in and custom hooks for various tasks	Custom composables for any reusable logic

Key Differences

Hooks in React are special functions like useState and useEffect that let you add state and side effects to functional components. They must follow rules like only calling hooks at the top level of components. Hooks are tightly integrated with React's rendering and lifecycle.

Composables in Vue are plain functions that use Vue's reactive APIs like ref and reactive inside the setup() function. They help organize and reuse logic by returning reactive data and methods. Composables are more flexible since they are just functions using Vue's reactivity system.

While hooks are React-specific and follow strict rules, composables are a pattern in Vue's Composition API that encourages modular code. Both aim to share logic but differ in framework integration and syntax.

Code Comparison

jsx

import React, { useState, useEffect } from 'react';

function useCounter() {
  const [count, setCount] = useState(0);

  useEffect(() => {
    const timer = setInterval(() => {
      setCount(c => c + 1);
    }, 1000);
    return () => clearInterval(timer);
  }, []);

  return count;
}

export default function Counter() {
  const count = useCounter();
  return <div>Count: {count}</div>;
}

Output

Count: 0 (increments by 1 every second)

Vue Composable Equivalent

vue

import { ref, onMounted, onUnmounted } from 'vue';

export function useCounter() {
  const count = ref(0);
  let timer = null;

  onMounted(() => {
    timer = setInterval(() => {
      count.value++;
    }, 1000);
  });

  onUnmounted(() => {
    clearInterval(timer);
  });

  return { count };
}

export default {
  setup() {
    const { count } = useCounter();
    return { count };
  },
  template: `<div>Count: {{ count }}</div>`
};

Output

Count: 0 (increments by 1 every second)

When to Use Which

Choose Hooks when working in React projects to manage component state and lifecycle with built-in or custom hooks. Hooks are the standard way to add logic in React functional components.

Choose Composables when working in Vue 3 projects to organize and reuse reactive logic using the Composition API. Composables fit naturally with Vue's reactivity and lifecycle.

Use each pattern in its respective framework to follow best practices and leverage the framework's strengths.

Key Takeaways

Hooks are React functions to manage state and effects inside components.

Composables are Vue functions that encapsulate reactive logic using Composition API.

Hooks follow strict rules and integrate tightly with React lifecycle.

Composables are flexible functions using Vue's reactive system inside setup().

Use hooks in React and composables in Vue for best framework compatibility.