lifecycle questions

Component lifecycle in functional components is managed using hooks like useEffect, which can perform side effects on mount, update, and unmount. useEffect replaces lifecycle methods like componentDidMount, componentDidUpdate, and componentWillUnmount.

The `ngOnInit` lifecycle hook in Angular is used for component initialization tasks that need to occur after Angular has finished setting up the component's input properties. It is called once, immediately after the component is instantiated and its input properties are bound. This hook is ideal for initializing data, performing setup operations, or making service calls that are required for the component to function correctly. Implementing `ngOnInit` helps ensure that the component is fully initialized and ready for use when it is rendered in the application.

Vue.js lifecycle hooks are methods that allow developers to execute code at specific stages of a component's lifecycle. These hooks include `created`, `mounted`, `updated`, and `destroyed`, among others. Each hook corresponds to a particular phase of the component's lifecycle, such as initialization, DOM insertion, and cleanup. By leveraging these hooks, developers can perform actions such as fetching data, setting up subscriptions, or cleaning up resources at appropriate times.

A Stateful Widget is a widget that can change its state during the lifetime of the widget. It has a lifecycle that includes initialization, building, and disposal phases. For example, a checkbox that changes its value when tapped is a Stateful Widget, requiring a build method to reflect the new state.