Note: This feature is available in Web Workers.
The DOMPoint interface's y property holds the vertical coordinate, y, for a point in space.
Unless transforms have been applied to alter the orientation, the value of y increases downward and decreases upward.
A double-precision floating-point value indicating the y coordinate's value for the point. This value is unrestricted, meaning that it is allowed to be infinite or invalid (that is, its value may be NaN or ±Infinity).