The DOMPointReadOnly method toJSON() returns an object giving the JSON form of the point object.

None.

A new object whose properties are set to the values in the DOMPoint or DOMPointReadOnly on which the method was called.

This example creates a DOMPoint object representing the top-left corner of the current window, in screen coordinates, then converts that to JSON.

var topLeft = new DOMPoint(window.screenX, window.screenY);

var pointJSON = topLeft.toJSON();