TypeScript
Write TypeScript type definitions and see them explained. Explore utility types, generics, and conditional types interactively.
Constructs an object type whose property keys are K and values are T.
Makes all properties in T optional.
Makes all properties in T required (removes optionality).
Constructs a type by picking all properties from T and then removing K.
Constructs a type by picking the set of properties K from T.
Extracts from T those types that are assignable to U.
Excludes from T those types that are assignable to U.
Extracts the return type of a function type.
Extracts the parameter types of a function type as a tuple.
Recursively unwraps the "awaited type" of a Promise.
Excludes null and undefined from T.