JAVASCRIPT
`useDebounce` Custom Hook for Input Throttling
Learn to create a `useDebounce` custom React hook to delay state updates, perfect for optimizing search inputs or preventing excessive API calls.
import { useState, useEffect } from 'react';
function useDebounce(value, delay) {
const [debouncedValue, setDebouncedValue] = useState(value);
useEffect(() => {
const handler = setTimeout(() => {
setDebouncedValue(value);
}, delay);
return () => {
clearTimeout(handler);
};
}, [value, delay]);
return debouncedValue;
}
// Example Usage:
/*
function SearchInput() {
const [searchTerm, setSearchTerm] = useState('');
const debouncedSearchTerm = useDebounce(searchTerm, 500); // 500ms delay
useEffect(() => {
if (debouncedSearchTerm) {
console.log('Fetching data for:', debouncedSearchTerm);
// Perform API call or heavy computation here
}
}, [debouncedSearchTerm]);
return (
<input
type="text"
placeholder="Search..."
value={searchTerm}
onChange={(e) => setSearchTerm(e.target.value)}
/>
);
}
*/
How it works: The `useDebounce` hook delays updating a `debouncedValue` state until a specified `delay` has passed without the `value` changing. It uses `useEffect` to set a timeout whenever `value` or `delay` changes. If the `value` changes again before the timeout completes, the previous timeout is cleared, and a new one is set, effectively resetting the timer. This prevents rapid updates, which is ideal for search bars or auto-save features.