How do you reverse the direction of a ball if continuously going in one direction?

I have declared my global variables, followed by a function to move the ball, then followed by a setInterval. However, I can’t seem to figure the right way to reverse the ball that continuously moves to the right of my screen until no longer visible. Is it a matter of a type of reverse method or setting up conditions?

>Solution :

Let me give you some insights:

to set up a collision you could get the y of the ball + or – radius and see if it’s greater than of that of the border or less than zero…

like this:

if (y + radius > innerHeight) and else if (y - radius < 0)

then you could compare the x similarly:

if (x + radius > innerWidth) and else if (x - radius < 0)

by velocity *= -1 or velocity = 0-velocity you can reverse the direction of the ball.

you can see this tutorial for more: https://www.geeksforgeeks.org/how-to-build-a-bounce-ball-with-html-and-javascript/