Resource Cleanup Patterns in JavaScript

JavaScript doesn’t have IDisposable, but you still need explicit cleanup for resources.

Common cleanup patterns

• try/finally for synchronous resource release.
• AbortController for canceling async work.
• Unsubscribe from event listeners and streams.

const controller = new AbortController();
try {
  await fetch('/api/data', { signal: controller.signal });
} finally {
  controller.abort();
}

Interview prompt

• How do you prevent leaks from event listeners in React?