Mod 9

Question 1

If we want to execute some functionality when a React component is first mounted, which hook should we use?

Answer 1

useEffect

Question 2

Can we run multiple Express servers, e.g., the one hosting a REST API and another hosting a development React app, on the same port on the same machine?

Answer 2

Hell no, you need different ports (ex: 3000 for Rest API and 8000 for React app)

Question 3

What is a common technique to share state between different components that are not in an ancestor-descendant relationship?

Answer 3

Define the state to be shared in a common ancestor of the components and pass it down to the components that need to share it.

Question 4

What are the three stages in the lifecycle of a React component?

Answer 4

Mounting: initial Display

Updating: when setState() is called

Unmounting: When component is being removed

Question 5

Consider the case when a page is first displayed and we want to display data in the page by calling a REST endpoint. When should we call the REST API and why?

Answer 5

We should call the REST API during the mounting stage since we want to display the data when the page is first displayed (this is when mounting occurs).