TypeScript using Keyword Guide

The using keyword enables automatic resource disposal when leaving scope. Here's how to use it effectively.

Best Practices#

Usage:
✓ Use for resource cleanup
✓ Implement Symbol.dispose
✓ Use await using for async
✓ Keep dispose idempotent

Patterns:
✓ File handles
✓ Database connections
✓ Locks and transactions
✓ Event subscriptions

Benefits:
✓ Automatic cleanup
✓ Exception safety
✓ Cleaner code
✓ No try/finally needed

Avoid:
✗ Long-lived resources
✗ Complex dispose logic
✗ Side effects in dispose
✗ Forgetting async disposal

The using keyword provides automatic resource disposal in TypeScript. Implement Symbol.dispose for synchronous cleanup or Symbol.asyncDispose for async cleanup. Resources are disposed in reverse order of acquisition, and disposal happens even when exceptions occur. Use DisposableStack for managing multiple related resources.

TypeScript using Keyword Guide

Basic Usage#

File Handling#

Database Connections#

Lock Management#

Async Disposable#

Transaction Pattern#

Timer Cleanup#

Event Listener Cleanup#

DisposableStack#

HTTP Client#

Temporary Directory#

Best Practices#

Conclusion#

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