How to change HTML CSS and JavaScript code in App

Question

How to change any HTML CSS and JavaScript code in App ,

Answer 1

This lesson may be helpful :
https://www.sololearn.com/learn/1439/?ref=app

Answer 2

Thanks Nova this lesson is so helpful for me😊

Answer 3

Rearrange the code to create a valid video tag that will attempt to play the mp4 file first.
<source src="a.mp4" type="video/mp4">
<video controls>
</video>
<source src="a.ogg" type="video/ogg">
Video is not supported