Conditional types enable complex type logic based on conditions. Here's how to use them effectively.
Basic Conditional Types
Loading code block...
Distributive Conditional Types
Loading code block...
Type Inference with infer
Loading code block...
Practical Patterns
Loading code block...
Function Overloads
Loading code block...
Recursive Types
Loading code block...
Advanced Inference
Loading code block...
Utility Type Implementations
Loading code block...
Type Guards
Loading code block...
Practical Examples
Loading code block...
Best Practices
Design:
✓ Use infer for extracting types
✓ Leverage distribution over unions
✓ Wrap in tuple to prevent distribution
✓ Use recursion carefully
Readability:
✓ Name complex conditions clearly
✓ Break down nested conditions
✓ Use intermediate types
✓ Document non-obvious logic
Performance:
✓ Avoid deep recursion
✓ Cache computed types
✓ Limit union size
✓ Use constraints
Avoid:
✗ Over-complicated conditions
✗ Deeply nested ternaries
✗ Unclear type logic
✗ Excessive distribution
Conclusion
Conditional types enable powerful type-level programming in TypeScript. Use them for type transformations, inference, and complex type logic. Combine with infer for extracting types and recursion for deep operations. Keep types readable by breaking down complex conditions.