useParams

useParams<ParamsOrKey = string>(): Readonly<[ParamsOrKey] ? [string] : Partial<ParamsOrKey>>

Returns an object of key/value pairs of the dynamic params from the current URL that were matched by the routes. Child routes inherit all params from their parent routes.

import { useParams } from "react-router"

function SomeComponent() {
  let params = useParams()
  params.postId
}

Assuming a route pattern like /posts/:postId is matched by /posts/123 then params.postId will be "123".