I have never done a project of real scale, and have been wandering on some small projects. Therefore, there is no systematic understanding of what it means to load on demand and ask for help.

  node.js, question

I just know that I need to use it with a requirejs, and whether I have explained the articles or books loaded on demand from the concept and principle. Please recommend to learn

I understand what you mean from the front:

The front-end js of jquery era were all introduced in html inside < script src=’xxxx.js’></script >. such a website should load all js at the beginning.

Now, if es6(react/webpack) is used, it can be introduced by import, so that a certain class will be added. I wonder if you mean that.