On the php background, why is the editor so cool-hearted that it is not displayed, depressing the ing.-php Tutorial?

In the php background, why is the editor so easily displayed? depressing ing. reading a code written by others is to add the editor to the background.
There are two steps. one is to introduce the js path of the editor, and then add this sentence where you want to display the editor.


What puzzles me is: how can I display the editor in the above position after adding this js? what is the parsing process,

Reply to discussion (solution)

Find the class in the html tag and parse it. Why does LZ study the logic in this field? I generally only use it. if you have any questions, please refer to the official documentation to modify the parameters...

Find the class in the html tag and parse it. Why does LZ study the logic in this field? I generally only use it. if you have any questions, please refer to the official documentation to modify the parameters...

If I don't understand the truth, I don't know how to use it.

It may be that after the class is found, appendChild is added.

You can see how ckeditor. js is written.
How can I know what the light looks like?

This is a js file. let's take a look. I changed the suffix to png.