Why do the balls don't bounce separately , when a ball bounce all of the other balls bounce too

Question

https://code.sololearn.com/WkP0qqKsF8cw/?ref=app
sorry for the bad code writing I'm still a newbie for coding

Answer 1

The key for the solution is
this.vx = 1
this.vy = 1

https://code.sololearn.com/WK6oTC8TN69y/?ref=app

Answer 2

Mohammad _io_ and also add some styles to get nice effect

*{
margin:0;
padding:0;
box-sizing:border-box ;
}

Answer 3

Thank you JaScript. now I understand why

Answer 4

HrCoder thanks