Please solve my JavaScript problem

Question

Please solve this (JavaScript)

I want to make classes all with their own x varibles and their own Intervals to change them, but I am having a problem.
When I write " this.x" it cannot find a varible.
How can I get this varible?

(Below prints NaN and I know the functions are working properly)

function example(x) {
this.x=x

this.rightStart= function() {
this.mover= setInterval( function() {
this.x+=1
console.log(this.x)
}, 10)
}

this.rightEnd= function() {
clearInterval(this.mover);
}
}

Answer 1

This will help you:

https://code.sololearn.com/WlwkC73NA68V/?ref=app

Answer 2

Thank yous