Subtype

Definitions

1. A type that can be safely used wherever its supertype is expected, satisfying the Liskov Substitution Principle. If `Cat` is a subtype of `Animal`, then any function accepting an `Animal` will also accept a `Cat` without error.

   In plain English: A more specific type that can stand in for a more general one, because it has at least everything the general type promises.

   Example: "string is a subtype of string | number in TypeScript, so you can pass a string anywhere the union is expected."

Related Terms

• Operator Overloading
• Virtual Function
• Method Dispatch
• Method Override
• Method Signature
• Overload
• Runtime Type Check
• Type Parameter
• Virtual Method