Animations are started by calling start() on your animation. start() takes a completion callback that will be called when the animation is done or when the animation is done because stop() was called on it before it could finish.
Optional
callback: EndCallbackOptional function that will be called after the animation finished running normally or when the animation is done because stop() was called on it before it could finish
Animated.timing({}).start(({ finished }) => {
// completion callback
});
Stops any running animation.
Stops any running animation and resets the value to its original.