Why isn't not moving the variable square

Question

https://code.sololearn.com/WfKnTJGpCry4/?ref=app

Answer 1

you should not use the id to style the square. You will end up with a bunch of duplicated ids. id should be unique. use class to style the square.

also, after updating the x and y value,
this.y += this.dy
the style should also be updated to reflect the changes. This is what makes the element move.
this.square.style.top = this.y+"px";

that's why you should maybe use
this.square
instead of var square to create element.

also, try not to use var. it makes the variables global. use let instead.

I played around with your code:
https://code.sololearn.com/WzrcGtRUaVxd/?ref=app
https://code.sololearn.com/WzX7fbKDsK37/?ref=app

Answer 2

Leonard Function "update" is incrementing the increment itself, instead of the actual square position:
this.dy += this.y