How can you call U differently when typing type InferValueTypes = T extends { [key: string]: infer U }? U: never?

Question

typescript

type InferValueTypes = T extends { [key: string]: infer U } ? U : never
What is another name for U ?

Answer 1

U is the name you enter, it can be any valid name instead:

type InferValueTypes<T> = T extends { [key: string]: infer IDontKnowWhat2CallThis } ? IDontKnowWhat2CallThis : never

In general, you should not use conditional types, especially with infer, where you can do without them:

type InferValueTypes<T extends Record<string, unknown>> = T[string];