How can I detect if the touch that was released was the same touch that had started?

Question

I have made a joystick, and when the touch is released I make it return back to center, the problem is that if I touch the screen with another finger and release it then it will still return the joystick to the center, how can I make sure this only happens once the touch that is moving the joystick is released? Here is the code:
https://code.sololearn.com/WttB7NsJJq1k/?ref=app

Answer 1

I'm getting no replies, but it's okay because I figured out a way to do this on my own, I created a variable that is updated to clientX property of the touch which is moving the joystick every time touchmove event is triggered, then after a touch is released I check wether changedTouches[0].clientX matches that variable's value. I don't know if that's the best way to do this but it seems to work.