Interfaces
An interface declares a set of method signatures that a type must satisfy, enabling shared behavior across unrelated types. Each aspect has a dedicated chapter:
| Topic | Description |
|---|---|
| Declaration | Declaring the methods an interface requires |
| Implementation | Satisfying an interface with extend |
See Also
- Methods — attaching behaviour to a type with
extend - Structures — the types that most often implement interfaces
Built-in Aliases
Some built-in type names are themselves compiler-provided aliases — convenient default spellings for a specific underlying type. Like any alias they are transparent, so the alias and its target are the same type.
Declaration
An interface declares a set of method signatures that a type must satisfy. It lists method headers — names, parameters, and return types — but no bodies; the implementing type supplies those.