lunar whale
I have an array of objects I'm trying to reduce, the sig looks like
sortedList.reduce((acc, movement, index) => {};
The infered type of acc is the type of sortedList, but Is it fine to specify acc should be an array and different object structure i specify, and how do i do this in the reduces signature?
orchid swift
you can specify the type parameter of reduce
lunar whale
I've used type assertion on the initialValue of my reduce, is that the way you'd approach or do you mean type something else?
orchid swift
reduce<number>(...), just specifying the type parameter of reduce?
lunar whale
sortedList.reduce((acc, movement, index) => {}, [] as (ProductFrom | ProductTo)[]);
is what i have
works all fine but i wonder if i should be expliclity typing differently or typing something else
orchid swift
...the type parameter of reduce
that code doesn't work though, (ProductFrom, ProductTo) isn't valid
did you mean [ProductFrom, ProductTo]
orchid swift
they mean completely different things
lunar whale
Ah i wasn't aware
orchid swift
it absolutely matters 💀
lunar whale
What's the difference?
orchid swift
i don't know what you actually want there though so i can't say if you want a tuple or a union
orchid swift
What's the difference?
uh, everything? you'd get a better answer from "what're the similarities" and that answer would be "they're typescript types" and nothing else, really
lunar whale
I want to say the return type is an array, where the types in the array can be ProductFrom or ProductTo
orchid swift
that would be a union then
anyways, this is more about code style consistency then
in your codebase, if you want a variable of type string[] let's say, would you do const arr: string[] = []; or const arr = [] as string[];
if the latter, then your current code would be following that pattern, but if the former you'd use the type parameter
lunar whale
The former, ok so that's basically what im getting at
they mean the same thing
That's really useful ty
Is there somewhere i can read up about TS tuples btw? all i can see from offical ts is a playground link about them
lunar whale
tyvm