The x read-only property of the SVGFEFloodElement interface describes the horizontal coordinate of the position of an SVG filter primitive as a SVGAnimatedLength.
It reflects the x attribute of the <feFlood> element, which fills an SVG filter subregion with the color and opacity defined by flood-color and flood-opacity. The attribute is a <length> or <percentage>. The <coordinate> is a length in the user coordinate system that is the given distance from the origin of the user coordinate system along the x-axis. If the x attribute is a percent value, the property value is relative to the width of the filter region in user coordinate system units. The default value is 0.
const feFlood = document.querySelector("feFlood");
const leftPosition = feFlood.x;
console.log(leftPosition.baseVal.value); // the `x` valueSVGFEFloodElement.y<blend-mode> data typemix-blend-mode property