Gets the increment value of the slider thumb as the user moves the thumb.
For example, if snapInterval is 2, the minimum value is 0, and the maximum value is 10, the thumb snaps to the values 0, 2, 4, 6, 8, and 10 as the user move the thumb. A value of 0, means that the slider moves continuously between the minimum and maximum values.
The default value is 0.