In this short tutorial you will learn how to determine which tile your player is standing on in the map and how to change its value. I also wrote the example application as a little game, so there are plenty of other things to see in the source code, like how to implement keyboard controls, a simple game loop, and some basic collision detection as well as how to draw it all to the screen.
View the source code on my Github page here: https://github.com/frankarendpoth/frankarendpoth.github.io/blob/master/content/pop-vlog/javascript/2017/019-walk-on-tiles/walk-on-tiles.js
Check out the working example here: https://frankpoth.info/content/pop-vlog/javascript/2017/019-walk-on-tiles/walk-on-tiles.html
If for some reason frankpoth.info doesn't work, try accessing content through my Github Pages url: frankarendpoth.github.io