Function overloads define multiple call signatures for a single function. Here's how to use them effectively.
Basic Syntax
Loading code block...
Different Return Types
Loading code block...
Object Parameter Overloads
Loading code block...
Optional Parameters
Loading code block...
Callback Signatures
Loading code block...
Generic Overloads
Loading code block...
Method Overloads
Loading code block...
Event Handler Overloads
Loading code block...
API Response Types
Loading code block...
Constructor Overloads
Loading code block...
Interface Method Overloads
Loading code block...
Narrowing with Overloads
Loading code block...
Best Practices
Design:
✓ Order overloads specific to general
✓ Keep implementation signature broad
✓ Document each overload
✓ Use for distinct behaviors
Patterns:
✓ Different return types
✓ Optional callback vs Promise
✓ Type narrowing by parameter
✓ Builder pattern APIs
Avoid:
✗ Too many overloads (> 4-5)
✗ Overloads for default values
✗ Complex conditional returns
✗ Overloads that could be unions
Alternatives:
✓ Union types when simpler
✓ Generics for type inference
✓ Conditional types for complex cases
✓ Separate functions for clarity
Conclusion
Function overloads provide multiple type-safe ways to call a function. Use them when the return type depends on input types, or when different parameter combinations have distinct behaviors. Order overloads from most specific to least specific, and keep the implementation signature compatible with all overloads.