JSFiddle - React, Tailwind, and code Playground

HTML

<video width="320" height="240" controls id="videoPlayer">
  <source src="http://www.w3schools.com/html/movie.mp4" type="video/mp4">
  Your browser does not support the video tag.
</video>

JavaScript

var nextVideo = ["http://www.w3schools.com/html/movie.mp4","http://www.w3schools.com/html/mov_bbb.mp4"];
var curVideo = 0;
var videoPlayer = document.getElementById('videoPlayer');
videoPlayer.onended = function(){
    if(curVideo == 0){
        videoPlayer.src = nextVideo[1];
        curVideo = 1;
    } else if(curVideo == 1){
        videoPlayer.src = nextVideo[0];
        curVideo = 0;
    }
}