JavaScript Performance Optimization Tips

Performance optimization is crucial for modern web applications. Learn practical techniques to make your JavaScript code faster and more efficient.

Code Splitting

Reduce initial bundle size by splitting your code effectively:

// Instead of importing the entire library
import { debounce, throttle } from "lodash";

// Use dynamic imports for route-based code splitting
const AdminDashboard = React.lazy(() => import("./AdminDashboard"));

Memoization Techniques

Cache expensive computations to avoid unnecessary recalculations:

const memoizedValue = useMemo(() => {
  return expensiveCalculation(prop1, prop2);
}, [prop1, prop2]);

// Custom memoization function
function memoize(fn) {
  const cache = new Map();

  return (...args) => {
    const key = JSON.stringify(args);
    if (cache.has(key)) return cache.get(key);

    const result = fn(...args);
    cache.set(key, result);
    return result;
  };
}

Event Delegation

Improve performance by using event delegation:

document.getElementById("list").addEventListener("click", (e) => {
  if (e.target.matches(".list-item")) {
    handleItemClick(e.target);
  }
});