The appendItem() method of the SVGPointList interface adds a DOMPoint to the end of the list.
appendItem(obj)objA DOMPoint object containing the coordinates of the point to be appended.
The DOMPoint object that was appended.
NoModificationAllowedError DOMExceptionThrown if the list is read-only.
The following example shows an SVG which contains a <polyline> with five coordinate pairs. A new DOMPoint is created, and appended to the list.
<svg id="svg" viewBox="-10 -10 120 120" xmlns="http://www.w3.org/2000/svg">
<polyline
id="example"
stroke="black"
fill="none"
points="50,0 21,90 98,35 2,35 79,90" />
</svg>const example = document.getElementById("example");
const point = document.getElementById("svg").createSVGPoint();
point.y = 10;
point.x = 10;
console.log(example.points.appendItem(point));