DOMPoint: y property
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.
Value
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).