Does React or Vue have their own constructs?

Question

React

React.js and Vue.js are based on javascript and respectively use the following main parts of it:
- data types
- data storage locations (variables, objects, arrays, classes)
- operators
- constructs
- built-in functions and methods

Essentially both the React library and the framework Vue differs from pure javascript in that they have a set of modules, where additional ready-made functions, classes, etc. are written in files. And we can say that this is a type of built-in functions / methods, only these are already built-in functions of a library or framework.

Can these two technologies have their own designs. Like if-elseor cycle for?
Or can they only use javascript language constructs?

Answer 1

React has jsx, View has custom tag attributes. If these are considered "language constructs", then they can. Only in the browser they will not work, you need to compile to "normal" javascript.