Type Parameter

Definitions

1. A placeholder type variable declared in angle brackets (e.g., `<T>`) on a generic function, class, or interface that is replaced with a concrete type when the generic is instantiated. It enables writing code that works uniformly over many types while preserving type safety — `Array<T>` becomes `Array<string>` or `Array<number>` at the call site.

   In plain English: A placeholder letter (like T) in generic code that gets filled in with an actual type when the code is used.

   Example: "The function takes a type parameter T so it can return the same type it receives — no downcasting needed."

Related Terms

• Forall
• Multiple Dispatch
• Operator Overloading
• Template
• Overload
• Runtime Type Check
• Subtype
• Type Bound
• Conditional Type