TypeScript Enums Guide

Enums allow you to define a set of named constants. Here's how to use them effectively in TypeScript.

Best Practices#

When to Use Enums:
✓ Fixed set of related constants
✓ Need reverse mapping
✓ IDE autocomplete benefits
✓ Namespace for values

Prefer const enum:
✓ When you don't need runtime object
✓ For performance-critical code
✓ When values are simple

Prefer Union Types:
✓ Simple string literals
✓ No need for iteration
✓ Better tree-shaking needed
✓ Working with APIs

Avoid:
✗ Heterogeneous enums
✗ Complex computed values
✗ Enums for single values
✗ Overusing numeric enums

TypeScript enums provide type-safe constants with IDE support and optional runtime features. Use string enums for readability, const enums for performance, and consider union types or as const objects as alternatives. Choose based on whether you need runtime iteration, reverse mapping, or minimal bundle size.

TypeScript Enums Guide

Numeric Enums#

String Enums#

Heterogeneous Enums#

Computed Enums#

Const Enums#

Reverse Mapping#

Enum as Types#

Enum Iteration#

Enums vs Union Types#

Enum Patterns#

Enum Type Guards#

Common Use Cases#

Best Practices#

Conclusion#

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