Mobile Development

React Native Hooks

useState, useEffect, and other React hooks in React Native applications.

useState

import { useState } from 'react';

# Basic state
const [count, setCount] = useState(0);
const [text, setText] = useState('');

# Update state
setCount(count + 1);
setText('new value');

useEffect

import { useEffect } from 'react';

# Run on mount
useEffect(() => {
    console.log('mounted');
}, []); # empty = run once

# Run on update
useEffect(() => {
    fetchData();
}, [count]); # when count changes

useRef

import { useRef } from 'react';

# Create ref
const inputRef = useRef(null);

# Use ref

inputRef.current.focus();