TypeScript Types and Generics/Generic identity function

Use a type parameter for reusable function typing.

Section: Generics

Generic identity function

typescript
typescript
function identity<T>(value: T): T {
  return value;
}
Explanation

Generics let a function preserve type information across inputs and outputs.

Learn the surrounding workflow

Compare similar commands or jump into common fixes when this command is part of a bigger troubleshooting path.

Related commands

Same sheet · prioritizing Generics
Generic array helper
Write array helpers that preserve element types.
OpenIn sheettypescriptsame section
Generic interface
Parameterize a reusable interface.
OpenIn sheettypescriptsame section
Constrain generic types
Require a minimum shape for a type parameter.
OpenIn sheettypescriptsame section
Constrain a key parameter with `keyof`
Accept only valid property names for a given object type.
OpenIn sheettypescriptsame section
Use `keyof`
Get a union of property names from a type.
OpenIn sheettypescript1 tag match
Simple mapped type
Create a type by iterating over keys.
OpenIn sheettypescript1 tag match