The ReactJS documentation says something interesting and powerful about what their JSX is capable of:

> 
> You can embed any JavaScript expression in JSX by wrapping it in curly
>  braces. For example, `2 + 2`, `user.firstName`, and `formatName(user)` are all valid expressions.
> 
> 
> 

<https://reactjs.org/docs/introducing-jsx.html#embedding-expressions-in-jsx>

This is so powerful and interesting to me because this isn't possible in AngularJS, nor EmberJS. Angular uses Angular Expressions in their markup, and EmberJS uses Handlebar Expressions their markup.

**Q1)** How does ReactJS achieve reading *any* JS Expression inside JSX?

**Q2)** Do they use eval() under the hood?