web api instance property
HTMLImageElement: y property
The read-only y property of the HTMLImageElement interface indicates the y-coordinate of the <img> element’s top border edge relative to the root element’s origin.
The x and y properties are only valid for an image if its display property has the computed value table-column or table-column-group. In other words: it has either of those values set explicitly on it, or it has inherited it from a containing element, or by being located within a column described by either <col> or <colgroup>.
Value
An integer value indicating the distance in pixels from the top edge of the element’s nearest root element to the top edge of the <img> element’s border box. The nearest root element is the outermost <html> element that contains the image. If the image is in an <iframe>, its y is relative to that frame.
In the diagram below, the top border edge is the top edge of the blue padding area. So the value returned by y would be the distance from that point to the top edge of the content area.
Example
See HTMLImageElement.x for example code that demonstrates the use of the HTMLImageElement.y (and HTMLImageElement.x).