Questions And Answers

Which kind of code do you write when using React.js?

Declarative Javascript Code.

With React.js you define the 'goal' (i.e. What should be shown on the screen) and let react figure out how to get there.

What is 'JSX'?

It is a special, non-standard syntax which is enabled in React Project.

Why is React all about 'Components'?

Every UI in the end up is made up of multiple building blocks (= components), hence it makes sense to think about user interfaces as "Combinations of components".

What does "Declarative" means?

You define the desired outcome (e.g. a target UI) and let the library (React) figure out the steps.
You define the target "State" (UI) and React figure out which JS commands need to be executed to bring that result to life.

What is a "React Component"?

It is a JS function which typically returns HTML(JSX) code that should be displayed.

How many custom React component must a React app have?

Thats totaly up to you.