useState (1/4)
What is the purpose of the `useState` hook in React?
    • useState is a React Hook that lets you add a state variable to your component.
    • The `useState` hook allows functional components to add stateful behaviour by providing a way to declare and update state variables.
    • It returns a state variable and a function to update it, enabling components to re-render when the state changes.
    initialState: The value you want the state to be initially.
    • It can be a value of any type, but there is a special behaviour for functions.
    • This argument is ignored after the initial render.
    • If you pass a function as initialState, it will be treated as an initializer function. It should be pure, should take no arguments, and should return a value of any type.
    • React will call your initializer function when initializing the component, and store its return value as the initial state.
    useState returns an array with exactly two values:
    • The current state. During the first render, it will match the initialState
    • The set function lets us update the state and trigger a re-render. set functions do not have a return value.