Suppose I have some function:
const someFunc = (input) => {// do something}
Where I know the input is an object that will have the property thing, ie. in the function I might check what input.thing is. How do I type hint the function when I declare it? I tried something like:
const someFunc = (input: { thing: string }) => {// do something}
But that doesn't seem to work.
That works just fine. You are declaring the first argument is an object with thing as a required string.
const someFunc = (input: { thing: string }) => {
}
It can be helpful to work it out with a type instead of inline, just because inline types look kind of like destructuring.
type Input = {
thing: string
}
const someFunc = (input: Input) => {}
You might want to allow other keys, but require thing in which case you can add [key: string]: any to your object.